[gentoo-user] new machine : CPU : AMD FX-4100 ?

[gentoo-user] new machine : CPU : AMD FX-4100 ?

[Philip Webb]

Thanks for all the comments so far: HTH other users.

I am struck by the huge difference in price between Intel/AMD :
at Canada Computers -- a very reliable store in my experience since 2000 --
Intel's price range is  CAD 200 - 240 ,
AMD's  CAD 130 - 180  with an outlier FX-8150 at  CAD 220 .
For  CAD 240 , I can buy an Intel i5-2550K, 4-core, 6 MB cache, 3,4 GHz ;
for  CAD 130 , an AMD FX-4100, 4-core, 8 MB cache, 3,6 GHz ;
both are  32 nm  & yes, I hear everyone saying that's irrelevant.
CC seems to have much higher demand for AMDs :
they have  c 3  Intels of each type in stock,  c 7  AMDs of each type
(they're a busy store, which moves stuff quickly).

I've looked at a few reviews, which reveal no special advantage for Intel.
http://www.legitreviews.com/article/1766/1/ says :
"entry level; half an FX-8150; best price; AMD Power Manager noticed
the CPU was idle & put it in a low power state for power-saving;
able to run  <= 3,8 GHz  when  1 - 2  threads are being used,
but only  <= 3,7 GHz  if  3 - 4  threads are being used:
running  1  thread can goto  3,8 GHz ;
fully unlocked, so you can easily overclock it".
http://www.cpubenchmark.net/cpu.php?cpu=AMD+FX-4100+Quad-Core
shows FX-4100 as best value.  AMD says it's made in Germany.

Do I need  > 4 cores ?  i5-2550K & FX-4100 both use  95 W
(some of the more costly AMDs use  125 W ).

I lean towards the FX-4100 : does anyone have further advice ?

Also, some comments implied that Intels have a built-in GPU :
if so, would that save the cost of a graphics card ?
how would it compare to an Nvidia card ?  how reliable are the drivers ?

-- 
========================,,============================================
SUPPORT     ___________//___,   Philip Webb
ELECTRIC   /] [] [] [] [] []|   Cities Centre, University of Toronto
TRANSIT    `-O----------O---'   purslowatchassdotutorontodotca

[gentoo-user] Re: new machine : CPU : AMD FX-4100 ?

[Nikos Chantziaras]

On 30/07/12 05:23, Philip Webb wrote:
> Do I need  > 4 cores ?

If you do video encoding, run chess analysis or are building software 
all day long, a 6 core helps.  But you don't "need" them.  You only need 
1 core.


> i5-2550K & FX-4100 both use  95 W
> (some of the more costly AMDs use  125 W ).

Note that power savings are not important if you're not using a laptop. 
  CPU power savings on a desktop don't translate to any relevant amount 
of money on your electricity bills.  This is because neither of those 
CPUs really use 95W.  That's just the thermal upper limit.


> Also, some comments implied that Intels have a built-in GPU :
> if so, would that save the cost of a graphics card ?
> how would it compare to an Nvidia card ?  how reliable are the drivers ?

Yes, Intel CPUs now have graphics integrated into the CPU itself.  The 
Intel drivers are top notch and are integrated into the kernel.  Of 
course this also means that there are no third-party driver packages 
like for NVidia, so in order to update your graphics driver, you will 
need to update your kernel and X.Org stack.

Note that of course performance is abysmal if you're interested in 
running video games.  With "video games" I don't mean Tux Racer, I mean 
stuff like Assassin's Creed, Skyrim, etc.  If that's not your thing, 
then Intel graphics will be enough for you.

Re: [gentoo-user] Re: new machine : CPU : AMD FX-4100 ?

[Michael Mol]

On Sun, Jul 29, 2012 at 10:50 PM, Nikos Chantziaras <realnc@gmail.com> wrote:
> On 30/07/12 05:23, Philip Webb wrote:
>> i5-2550K & FX-4100 both use  95 W
>> (some of the more costly AMDs use  125 W ).
>
>
> Note that power savings are not important if you're not using a laptop.  CPU
> power savings on a desktop don't translate to any relevant amount of money
> on your electricity bills.  This is because neither of those CPUs really use
> 95W.  That's just the thermal upper limit.

To be fair, power savings are relevant if you're concerned about your
electric bill, or if you're concerned about heat management in your
system.

Consider my dual E5345...leaving that on 24x7 appears to cost me about 90USD/mo.

-- 
:wq

[gentoo-user] Re: new machine : CPU : AMD FX-4100 ?

[Nikos Chantziaras]

On 30/07/12 06:08, Michael Mol wrote:
> On Sun, Jul 29, 2012 at 10:50 PM, Nikos Chantziaras <realnc@gmail.com> wrote:
>> On 30/07/12 05:23, Philip Webb wrote:
>>> i5-2550K & FX-4100 both use  95 W
>>> (some of the more costly AMDs use  125 W ).
>>
>>
>> Note that power savings are not important if you're not using a laptop.  CPU
>> power savings on a desktop don't translate to any relevant amount of money
>> on your electricity bills.  This is because neither of those CPUs really use
>> 95W.  That's just the thermal upper limit.
>
> To be fair, power savings are relevant if you're concerned about your
> electric bill, or if you're concerned about heat management in your
> system.
>
> Consider my dual E5345...leaving that on 24x7 appears to cost me about 90USD/mo.

CPU power savings will transform that into a 89.9USD/mo ;-)  That's what 
I mean.  It's not worth much.  It helps quite a bit with laptop battery 
life.  But for desktops, it doesn't do anything too useful.

Re: [gentoo-user] Re: new machine : CPU : AMD FX-4100 ?

[Michael Mol]

On Sun, Jul 29, 2012 at 11:55 PM, Nikos Chantziaras <realnc@gmail.com> wrote:
> On 30/07/12 06:08, Michael Mol wrote:
>>
>> On Sun, Jul 29, 2012 at 10:50 PM, Nikos Chantziaras <realnc@gmail.com>
>> wrote:
>>>
>>> On 30/07/12 05:23, Philip Webb wrote:
>>>>
>>>> i5-2550K & FX-4100 both use  95 W
>>>> (some of the more costly AMDs use  125 W ).
>>>
>>>
>>>
>>> Note that power savings are not important if you're not using a laptop.
>>> CPU
>>> power savings on a desktop don't translate to any relevant amount of
>>> money
>>> on your electricity bills.  This is because neither of those CPUs really
>>> use
>>> 95W.  That's just the thermal upper limit.
>>
>>
>> To be fair, power savings are relevant if you're concerned about your
>> electric bill, or if you're concerned about heat management in your
>> system.
>>
>> Consider my dual E5345...leaving that on 24x7 appears to cost me about
>> 90USD/mo.
>
>
> CPU power savings will transform that into a 89.9USD/mo ;-)  That's what I
> mean.  It's not worth much.  It helps quite a bit with laptop battery life.
> But for desktops, it doesn't do anything too useful.

If you really want the hard numbers, check out some place like Tom's
Hardware or Phoronix. I forget which does the power consumption
measurements. At some of the hardware review blogs, you can get
numbers on idle vs full-load power consumption, as measured at the
wall. The difference truly is striking.

Now, at least part of the problem with my E5345 setup is that I'm
running two high-performance Xeon processors that only have
operational clock speeds: 2.33 GHz and 2.00GHz. Desktop-targeted CPUs
often will clock down to just a hair over 1GHz, if not a hair under,
if you have proper power management daemons running.

-- 
:wq

[gentoo-user] Re: new machine : CPU : AMD FX-4100 ?

[Nikos Chantziaras]

On 30/07/12 07:28, Michael Mol wrote:
> On Sun, Jul 29, 2012 at 11:55 PM, Nikos Chantziaras <realnc@gmail.com> wrote:
>> On 30/07/12 06:08, Michael Mol wrote:
>>>
>>> On Sun, Jul 29, 2012 at 10:50 PM, Nikos Chantziaras <realnc@gmail.com>
>>> wrote:
>>>>
>>>> On 30/07/12 05:23, Philip Webb wrote:
>>>>>
>>>>> i5-2550K & FX-4100 both use  95 W
>>>>> (some of the more costly AMDs use  125 W ).
>>>>
>>>>
>>>>
>>>> Note that power savings are not important if you're not using a laptop.
>>>> CPU
>>>> power savings on a desktop don't translate to any relevant amount of
>>>> money
>>>> on your electricity bills.  This is because neither of those CPUs really
>>>> use
>>>> 95W.  That's just the thermal upper limit.
>>>
>>>
>>> To be fair, power savings are relevant if you're concerned about your
>>> electric bill, or if you're concerned about heat management in your
>>> system.
>>>
>>> Consider my dual E5345...leaving that on 24x7 appears to cost me about
>>> 90USD/mo.
>>
>>
>> CPU power savings will transform that into a 89.9USD/mo ;-)  That's what I
>> mean.  It's not worth much.  It helps quite a bit with laptop battery life.
>> But for desktops, it doesn't do anything too useful.
>
> If you really want the hard numbers, check out some place like Tom's
> Hardware or Phoronix. I forget which does the power consumption
> measurements. At some of the hardware review blogs, you can get
> numbers on idle vs full-load power consumption, as measured at the
> wall. The difference truly is striking.

When you have full load, the CPU won't clock down.  So nothing saved 
there.  If you don't have full load, the clock-down doesn't save much 
compared to max clocks while idle.

I hope you're getting the logic here :-)

Re: [gentoo-user] Re: new machine : CPU : AMD FX-4100 ?

[Michael Mol]

On Mon, Jul 30, 2012 at 2:16 AM, Nikos Chantziaras <realnc@gmail.com> wrote:
> On 30/07/12 07:28, Michael Mol wrote:
>>
>> On Sun, Jul 29, 2012 at 11:55 PM, Nikos Chantziaras <realnc@gmail.com>
>> wrote:
>>>
>>> On 30/07/12 06:08, Michael Mol wrote:
>>>>
>>>>
>>>> On Sun, Jul 29, 2012 at 10:50 PM, Nikos Chantziaras <realnc@gmail.com>
>>>> wrote:
>>>>>
>>>>>
>>>>> On 30/07/12 05:23, Philip Webb wrote:
>>>>>>
>>>>>>
>>>>>> i5-2550K & FX-4100 both use  95 W
>>>>>> (some of the more costly AMDs use  125 W ).
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> Note that power savings are not important if you're not using a laptop.
>>>>> CPU
>>>>> power savings on a desktop don't translate to any relevant amount of
>>>>> money
>>>>> on your electricity bills.  This is because neither of those CPUs
>>>>> really
>>>>> use
>>>>> 95W.  That's just the thermal upper limit.
>>>>
>>>>
>>>>
>>>> To be fair, power savings are relevant if you're concerned about your
>>>> electric bill, or if you're concerned about heat management in your
>>>> system.
>>>>
>>>> Consider my dual E5345...leaving that on 24x7 appears to cost me about
>>>> 90USD/mo.
>>>
>>>
>>>
>>> CPU power savings will transform that into a 89.9USD/mo ;-)  That's what
>>> I
>>> mean.  It's not worth much.  It helps quite a bit with laptop battery
>>> life.
>>> But for desktops, it doesn't do anything too useful.
>>
>>
>> If you really want the hard numbers, check out some place like Tom's
>> Hardware or Phoronix. I forget which does the power consumption
>> measurements. At some of the hardware review blogs, you can get
>> numbers on idle vs full-load power consumption, as measured at the
>> wall. The difference truly is striking.
>
>
> When you have full load, the CPU won't clock down.  So nothing saved there.

When you're considering full load, the TDP becomes a useful estimation
of relative power consumption between different processors.

> If you don't have full load, the clock-down doesn't save much compared to
> max clocks while idle.

This is where you're wrong.

http://www.tomshardware.com/reviews/ivy-bridge-benchmark-core-i7-3770k,3181-23.html

http://www.tomshardware.com/reviews/fx-power-consumption-efficiency,3060-11.html

-- 
:wq

[gentoo-user] Re: new machine : CPU : AMD FX-4100 ?

[James]

> > When you have full load, the CPU won't clock down.  So nothing saved there.

> When you're considering full load, the TDP becomes a useful estimation
> of relative power consumption between different processors.

> > If you don't have full load, the clock-down doesn't save much compared to
> > max clocks while idle.

> This is where you're wrong.

OK. both sides are well stated.

Amp meters are less than $50 USD. They clamp around the 
power cord, or any wires inside the computer you can fit
the "clamp" around.

So make your choice, based on actual measurements?
That's how an EE would make a decision on how
a given processor or software setup actually effects
the power consumption. REAL DATA.

Note, some of the fancier meter's have an integrator function
where measurements are taken frequently over a time period
to get an even more realistic picture of power consumption...

http://www.allaboutcircuits.com/vol_6/chpt_2/4.html


hth,
James

Re: [gentoo-user] Re: new machine : CPU : AMD FX-4100 ?

[Michael Mol]

On Mon, Jul 30, 2012 at 12:36 PM, James <wireless@tampabay.rr.com> wrote:
>
>
>> > When you have full load, the CPU won't clock down.  So nothing saved there.
>
>> When you're considering full load, the TDP becomes a useful estimation
>> of relative power consumption between different processors.
>
>> > If you don't have full load, the clock-down doesn't save much compared to
>> > max clocks while idle.
>
>> This is where you're wrong.
>
> OK. both sides are well stated.
>
> Amp meters are less than $50 USD. They clamp around the
> power cord, or any wires inside the computer you can fit
> the "clamp" around.
>
> So make your choice, based on actual measurements?
> That's how an EE would make a decision on how
> a given processor or software setup actually effects
> the power consumption. REAL DATA.
>
> Note, some of the fancier meter's have an integrator function
> where measurements are taken frequently over a time period
> to get an even more realistic picture of power consumption...
>
> http://www.allaboutcircuits.com/vol_6/chpt_2/4.html

I've got a Kill-o-Watt which I use for these kinds of purposes.

The problem with obtaining first-hand data for a purchasing decision
is getting the parts to perform the tests on.

-- 
:wq

Re: [gentoo-user] Re: new machine : CPU : AMD FX-4100 ?

[Mark Knecht]

On Mon, Jul 30, 2012 at 9:36 AM, James <wireless@tampabay.rr.com> wrote:
<SNIP>
>
> Amp meters are less than $50 USD. They clamp around the
> power cord, or any wires inside the computer you can fit
> the "clamp" around.

<SNIP>
>
> hth,
> James
>
>
I haven't read this thread but I do use one of these which costs less than $20:

http://www.amazon.com/P3-International-P4400-Electricity-Monitor/dp/B00009MDBU/ref=pd_sim_hi_1

Personally I think CPU power consumption is a red herring without
including the power consumed by the rest of the box:

MB power?
Hard drive power?
Hard disk power
GPU power?
DRAM power?

The 5 above can easily become the dominant power hogs.

I use an Intel i7 980X 6-core hyper-threaded CPU, so that's 12 CPUs in
top, which burns _lots_ of power, but I suspect it's not the biggest
power consumer when compared to the total of the 6 500GB 7200 RPM hard
drives I have in the box.

WRT to money spent to run a machine I hope someone stated earlier than
this that it's the whole system that matters and not just the CPU.

Cheers,
Mark

Re: [gentoo-user] Re: new machine : CPU : AMD FX-4100 ?

[Michael Mol]

On Mon, Jul 30, 2012 at 1:04 PM, Mark Knecht <markknecht@gmail.com> wrote:
> On Mon, Jul 30, 2012 at 9:36 AM, James <wireless@tampabay.rr.com> wrote:
> <SNIP>
>>
>> Amp meters are less than $50 USD. They clamp around the
>> power cord, or any wires inside the computer you can fit
>> the "clamp" around.
>
> <SNIP>
>>
>> hth,
>> James
>>
>>
> I haven't read this thread but I do use one of these which costs less than $20:
>
> http://www.amazon.com/P3-International-P4400-Electricity-Monitor/dp/B00009MDBU/ref=pd_sim_hi_1
>
> Personally I think CPU power consumption is a red herring without
> including the power consumed by the rest of the box:
>
> MB power?
> Hard drive power?
> Hard disk power
> GPU power?
> DRAM power?
>
> The 5 above can easily become the dominant power hogs.
>
> I use an Intel i7 980X 6-core hyper-threaded CPU, so that's 12 CPUs in
> top, which burns _lots_ of power, but I suspect it's not the biggest
> power consumer when compared to the total of the 6 500GB 7200 RPM hard
> drives I have in the box.

Spinning disks consume surprisingly little power once they're up to
speed. My GPU, by comparison, doesn't seem to reduce heat generation
very much when relatively idle.

>
> WRT to money spent to run a machine I hope someone stated earlier than
> this that it's the whole system that matters and not just the CPU.

I didn't state so explicitly, no, but I believe I mentioned the two
machines had been otherwise comparable in their equipment loadout. If
I missed that, my bad.

-- 
:wq

Re: [gentoo-user] Re: new machine : CPU : AMD FX-4100 ?

[Mark Knecht]

On Mon, Jul 30, 2012 at 10:14 AM, Michael Mol <mikemol@gmail.com> wrote:
> On Mon, Jul 30, 2012 at 1:04 PM, Mark Knecht <markknecht@gmail.com> wrote:
<SNIP>
>>
>> MB power?
>> Hard drive power?
>> Hard disk power
>> GPU power?
>> DRAM power?
>>
>> The 5 above can easily become the dominant power hogs.
>>
>> I use an Intel i7 980X 6-core hyper-threaded CPU, so that's 12 CPUs in
>> top, which burns _lots_ of power, but I suspect it's not the biggest
>> power consumer when compared to the total of the 6 500GB 7200 RPM hard
>> drives I have in the box.
>
> Spinning disks consume surprisingly little power once they're up to
> speed. My GPU, by comparison, doesn't seem to reduce heat generation
> very much when relatively idle.
>

OK, point taken about the disks at least when talking about a single
disk. I see we measure the same way with a Kill-a-Watt so that's at
least consistent.

And I think we're in more or less violent agreement, but reducing the
CPU power in the end won't save all that much on the electric bill, or
so I think.

I ran around really quickly to find some spec values for the machine
I'm on right now. No idea if the numbers are right. They are just what
I found quickly:

CPU - i7-980x - 130W

vs

Asus Rampage II Extreme - Can't find so far, so let's guess 25W for
the chipset, NICS, audio devices, etc.
WD RAID Edition 500GB - 8W * 6 = 48W
NVidia GTX 465 class card = 80W
24GB DRAM - Total guess, but about 1W/DIMM looks safe, so 6W total

So a __really__ rough guess is my machine should use about (130 + 25 +
48 + 80 + 6) Watts, or 289W assuming I added it up correctly. That's
under full load though. My UPS has a power meter in it. The UPS is
driving this machine, 3 monitors, a small switch, a wireless access
point and maybe one or two other small things I've forgotten or have
plugged in somewhere. When the machine is essentially idle that mater
reads 330W. When I start a VM that uses 6 processor cores and runs for
30 minutes at full tilt the power consumption is 385W. I no longer
remember what I have set up in terms of the CPU clocking stuff. It's
on the machine and let's the box go full tilt, but I'm not sure what
it does when the machine is idle.

Anyway, if you assume that the 55W jump was the difference between the
980x idling, and then using 3 cores full tilt, then 6 cores (12
threads) might be more like a 100W jump which seems about right
according to Intel's spec.

In terms of the electric bill, don't forget the PC power supply is
only 80-90% efficient, so 10-20% is thrown away there also.

Now, assume you get a CPU that draws half the power. This setup would
still likely draw something close to 330W when it's idling, and might
only jump up by 60W when running full tilt. That would save maybe
(330+60)/(330+100) or only about 10% on the whole system power
consumption. For that reason I don't think skimping on the CPU makes
much sense to me. I'll happily turn the box off 2 hours a day vs go
slower all the time, but that's just me.

>>
>> WRT to money spent to run a machine I hope someone stated earlier than
>> this that it's the whole system that matters and not just the CPU.
>
> I didn't state so explicitly, no, but I believe I mentioned the two
> machines had been otherwise comparable in their equipment loadout. If
> I missed that, my bad.

And I don't know that you did as I haven't read the thread, but part
of my argument is that you have to know the WHOLE system and not just
the CPU to decide if changing the CPU costs or saves much power.

Cheers,
Mark

Re: [gentoo-user] Re: new machine : CPU : AMD FX-4100 ?

[Michael Hampicke]

Am 30.07.2012 19:14, schrieb Michael Mol:
> On Mon, Jul 30, 2012 at 1:04 PM, Mark Knecht <markknecht@gmail.com> wrote:
>> On Mon, Jul 30, 2012 at 9:36 AM, James <wireless@tampabay.rr.com> wrote:
>> <SNIP>
>>>
>>> Amp meters are less than $50 USD. They clamp around the
>>> power cord, or any wires inside the computer you can fit
>>> the "clamp" around.
>>
>> <SNIP>
>>>
>>> hth,
>>> James
>>>
>>>
>> I haven't read this thread but I do use one of these which costs less than $20:
>>
>> http://www.amazon.com/P3-International-P4400-Electricity-Monitor/dp/B00009MDBU/ref=pd_sim_hi_1
>>
>> Personally I think CPU power consumption is a red herring without
>> including the power consumed by the rest of the box:
>>
>> MB power?
>> Hard drive power?
>> Hard disk power
>> GPU power?
>> DRAM power?
>>
>> The 5 above can easily become the dominant power hogs.
>>
>> I use an Intel i7 980X 6-core hyper-threaded CPU, so that's 12 CPUs in
>> top, which burns _lots_ of power, but I suspect it's not the biggest
>> power consumer when compared to the total of the 6 500GB 7200 RPM hard
>> drives I have in the box.
> 
> Spinning disks consume surprisingly little power once they're up to
> speed. My GPU, by comparison, doesn't seem to reduce heat generation
> very much when relatively idle.
> 

When I built my NAS box I did meassure the power consumption of my box,
first with one HD, then two, three and so one. And I figured that one of
my (Samsung) HDs uses about 5 Watts when running idle.

Re: [gentoo-user] Re: new machine : CPU : AMD FX-4100 ?

[Mark Knecht]

On Mon, Jul 30, 2012 at 11:12 AM, Michael Hampicke <gentoo-user@hadt.biz> wrote:
<SNIP>
>> Spinning disks consume surprisingly little power once they're up to
>> speed. My GPU, by comparison, doesn't seem to reduce heat generation
>> very much when relatively idle.
>>

Idle on a GPU (in Linux) might be more when the screen is black. I
don't even know how to drive my GPU hard. It's just not part of my
life here. Maybe certain games or something?

>
> When I built my NAS box I did meassure the power consumption of my box,
> first with one HD, then two, three and so one. And I figured that one of
> my (Samsung) HDs uses about 5 Watts when running idle.
>

That's very consistent with the WD numbers I found. Something like 6W
idle, 8W max, etc. for my RAID Edition drives which are not WD Green
drives which likely have lower numbers.

Point is that there's little power saved in a box with 6 drives going
from max use to idle, etc. But I know you know that! :-)

Anyway, we're getting similar results is what it sounds like to me.

- Mark

Re: [gentoo-user] Re: new machine : CPU : AMD FX-4100 ?

[Volker Armin Hemmann]

Am Montag, 30. Juli 2012, 10:08:24 schrieb Michael Mol:
> On Mon, Jul 30, 2012 at 2:16 AM, Nikos Chantziaras <realnc@gmail.com> wrote:
> > On 30/07/12 07:28, Michael Mol wrote:
> >> On Sun, Jul 29, 2012 at 11:55 PM, Nikos Chantziaras <realnc@gmail.com>
> >> 
> >> wrote:
> >>> On 30/07/12 06:08, Michael Mol wrote:
> >>>> On Sun, Jul 29, 2012 at 10:50 PM, Nikos Chantziaras <realnc@gmail.com>
> >>>> 
> >>>> wrote:
> >>>>> On 30/07/12 05:23, Philip Webb wrote:
> >>>>>> i5-2550K & FX-4100 both use  95 W
> >>>>>> (some of the more costly AMDs use  125 W ).
> >>>>> 
> >>>>> Note that power savings are not important if you're not using a
> >>>>> laptop.
> >>>>> CPU
> >>>>> power savings on a desktop don't translate to any relevant amount of
> >>>>> money
> >>>>> on your electricity bills.  This is because neither of those CPUs
> >>>>> really
> >>>>> use
> >>>>> 95W.  That's just the thermal upper limit.
> >>>> 
> >>>> To be fair, power savings are relevant if you're concerned about your
> >>>> electric bill, or if you're concerned about heat management in your
> >>>> system.
> >>>> 
> >>>> Consider my dual E5345...leaving that on 24x7 appears to cost me about
> >>>> 90USD/mo.
> >>> 
> >>> CPU power savings will transform that into a 89.9USD/mo ;-)  That's what
> >>> I
> >>> mean.  It's not worth much.  It helps quite a bit with laptop battery
> >>> life.
> >>> But for desktops, it doesn't do anything too useful.
> >> 
> >> If you really want the hard numbers, check out some place like Tom's
> >> Hardware or Phoronix. I forget which does the power consumption
> >> measurements. At some of the hardware review blogs, you can get
> >> numbers on idle vs full-load power consumption, as measured at the
> >> wall. The difference truly is striking.
> > 
> > When you have full load, the CPU won't clock down.  So nothing saved
> > there.
> 
> When you're considering full load, the TDP becomes a useful estimation
> of relative power consumption between different processors.
> 
> > If you don't have full load, the clock-down doesn't save much compared to
> > max clocks while idle.
> 
> This is where you're wrong.
> 
> http://www.tomshardware.com/reviews/ivy-bridge-benchmark-core-i7-3770k,3181-
> 23.html
> 
> http://www.tomshardware.com/reviews/fx-power-consumption-efficiency,3060-11.
> html

I wouldn't trust anything Tom's publishes.

That said, Intel's 'TDP' is not really a 'TDP' - for almost a decade Intel's 
'TDP' is not the 'real' TDP but a 'usually you won't get higher than this' - 
until you run some really heavy stuff. Like compiling openoffice... 

AMD followed suit some time ago. So both numbers are misleading at best.

That said, idle&low load consumption is fine with all CPU's. Mobos and PSUs 
influence that numbers a lot more. 

-- 
#163933

Re: [gentoo-user] new machine : CPU : AMD FX-4100 ?

[Alecks Gates]

On Sun, Jul 29, 2012 at 9:23 PM, Philip Webb <purslow@ca.inter.net> wrote:
-snip-
> Also, some comments implied that Intels have a built-in GPU :
> if so, would that save the cost of a graphics card ?
> how would it compare to an Nvidia card ?  how reliable are the drivers ?
>
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>

AMD have some CPUs with GPUs as well (APUs, right now you'd look at
the A-series like A4, A6, etc), and they are currently very good.  The
drivers aren't as good of quality but the hardware is better, and you
will still get more out of them than Intel.  That, and they are also
cheaper.

Still, depends on what you plan on doing with the GPU.

Re: [gentoo-user] new machine : CPU : AMD FX-4100 ?

[Michael Mol]

On Sun, Jul 29, 2012 at 10:23 PM, Philip Webb <purslow@ca.inter.net> wrote:
> Thanks for all the comments so far: HTH other users.
>
> I am struck by the huge difference in price between Intel/AMD :
> at Canada Computers -- a very reliable store in my experience since 2000 --
> Intel's price range is  CAD 200 - 240 ,
> AMD's  CAD 130 - 180  with an outlier FX-8150 at  CAD 220 .

AMD parts have long, long been generally cheaper than Intel parts. If
you can afford the Intel part, you either get more beef per dollar, or
more beef per watt. (Where 'beef' refers to the CPU's practical
computing power, not some meaty substance.)

Every now and then, AMD manages to upend Intel here. (Usually, by
being able to do either more work per dollar or more work per watt. I
don't think they've ever managed to upend Intel on both fronts at the
same time, but I could be mistaken.) AMD's Hammer core managed to best
Intel by changing the subject of the race to multicore, forcing Intel
to ditch NetBurst and develop Core. With Core2, Intel pulled ahead for
a while, but AMD caught up. Sandy Bridge reflected Intel pulling _far_
ahead of AMD in work-per-watt (not sure about work per dollar), and
Bulldozer is AMD's answer to that; AMD went superscalar on Intel
again, which is the same stunt they pulled back in 1999 with the
Athlon. (Same stunt, but they pulled it a different way.) I think
Athlon was the most recent time AMD pulled ahead in both work-per-watt
and work-per-dollar.

All of this is based on hazy recollection...I welcome any corrections.

> For  CAD 240 , I can buy an Intel i5-2550K, 4-core, 6 MB cache, 3,4 GHz ;
> for  CAD 130 , an AMD FX-4100, 4-core, 8 MB cache, 3,6 GHz ;
> both are  32 nm  & yes, I hear everyone saying that's irrelevant.
> CC seems to have much higher demand for AMDs :
> they have  c 3  Intels of each type in stock,  c 7  AMDs of each type
> (they're a busy store, which moves stuff quickly).

AMD parts are very popular because they're much cheaper, and because
you can very often upgrade systems in a more incremental fashion than
you can with Intel parts.

>
> I've looked at a few reviews, which reveal no special advantage for Intel.
> http://www.legitreviews.com/article/1766/1/ says :
> "entry level; half an FX-8150; best price; AMD Power Manager noticed
> the CPU was idle & put it in a low power state for power-saving;
> able to run  <= 3,8 GHz  when  1 - 2  threads are being used,
> but only  <= 3,7 GHz  if  3 - 4  threads are being used:
> running  1  thread can goto  3,8 GHz ;
> fully unlocked, so you can easily overclock it".
> http://www.cpubenchmark.net/cpu.php?cpu=AMD+FX-4100+Quad-Core
> shows FX-4100 as best value.  AMD says it's made in Germany.
>
> Do I need  > 4 cores ?  i5-2550K & FX-4100 both use  95 W
> (some of the more costly AMDs use  125 W ).

As Nikos noted, the 95W and 125W numbers are theoretical limits; the
CPU shouldn't idle anywhere close to those numbers.

Also as Nikos noted, you only "need" one core; that (and some hardware
support) is all that's fundamentally required for the a preemptive
multitasking kernel such as Linux to run properly. That said, having
multiple cores has very real benefit; if one process hangs in a
busyloop, your other processes won't feel that process's competition
quite so badly.

Really, once you get beyond two cores, it doesn't matter a whole lot
if you have three, four or eight cores; what matters in those contexts
is what each of those cores is capable of individually, and what
they're capable of in aggregate. How much each of those matters
depends on what you're using the computer for.

For most use cases, a small number (Say, 3 or 4) of cores running at a
very high GHz number will give you better results than a larger number
of cores at a lower GHz number. Exceptions exist. One such exception
would be parallel compiles.

>
> I lean towards the FX-4100 : does anyone have further advice ?

To my mind, the FX-8120 is the best part on the market right now:

http://www.cpubenchmark.net/cpu.php?cpu=AMD+FX-8120+Eight-Core

Compare that to the FX-8150:
http://www.cpubenchmark.net/cpu.php?cpu=AMD+FX-8150+Eight-Core

and the FX-4100:
http://www.cpubenchmark.net/cpu.php?cpu=AMD+FX-4100+Quad-Core

Now compare their performance-per-dollar on the larger chart:
http://www.cpubenchmark.net/cpu_value_available.html

>
> Also, some comments implied that Intels have a built-in GPU :
> if so, would that save the cost of a graphics card ?
> how would it compare to an Nvidia card ?  how reliable are the drivers ?

Nikos responded adequately on this...

-- 
:wq