[gentoo-user] Re: Overclocking CPU causes segmentation fault

[Nikos Chantziaras <realnc@gmail.com>]

On 23/01/13 19:16, Volker Armin Hemmann wrote:
> Am 23.01.2013 16:35, schrieb Nikos Chantziaras:
>> On 23/01/13 17:09, Nilesh Govindrajan wrote:
>>> On Wednesday 23 January 2013 07:52:03 PM IST, Nikos Chantziaras wrote:
>>>> [...]
>>>> In my experience, most of the time you can overclock.  The issue is
>>>> with the user not knowing exactly how to do it.  You need to
>>>> understand a few things and how they affect each other.  It's not just
>>>> a knob you can turn.
>>>
>>> That pretty much applies to me. I don't know much about hardware stuff.
>>> Regarding your 1 Ghz overclock, you probably have good components in
>>> terms of RAM & SMPS.
>>> When I bought this rig in 2008, I knew nothing about good components,
>>> blindly trusted local vendor... also internet shopping wasn't advanced
>>> here.
>>> So pretty much substandard components.
>>
>> The part that's really important is the mainboard.  RAM doesn't
>> matter.  In my case, I had pretty basic 800MHz DDR2 RAM.  Raising the
>> FSB would bring it above that, so I changed the DRAM ratio to 1:1, and
>> the RAM then ran at only 600Mhz.
>>
>> That was the starting point to rule out RAM problems.  After that, I
>> raised FSB but kept the VCore constant until I hit the first
>> instabilities.  When that happened, I raised VCore a bit.  Rinse and
>> repeat, until the VCore was still below the maximum recommendation by
>> Intel.  That happened at 3.4GHz (378MHz FSB * 9 CPU multiplier =
>> 3402MHz CPU clock.)  The E6600 CPU I got was an average sample.
>> Others were running it at 3.6GHz (or even higher with water cooling.)
>>
>> This was a process that took about 3 days to complete (needs a lot of
>> stability testing.)  The good thing about those older CPUs was that
>> the performance boost I got by OCing wasn't just scaling linearly with
>> the CPU frequency.  It was scaling *better* than that, because raising
>> the FSB also made the mainboard itself perform better and with lower
>> latencies.
>>
> and here we are - the point where the suspension of disbelief ends.
>
> All you may have gained you threw away with the slower ram - and you are
> trying to tell us that your rig was faster?

Yes.  It made the difference in all games.  I'm talking 40 vs 60FPS 
here.  It was huge.

The RAM wasn't much slower.  Stock was 800 and I was running it at 756.


> You do know that with today's CPUs the CPU is not the bottleneck - the
> slow as molasses, no speed bump for 10 years ram is.
>
> (just look at the internal clock rate of dram chips - and you realize
> that ddr1-3 are pretty much the same crap).

The slightly slower RAM had no effect.  As I said, the performance gain 
was huge.  If the RAM ends up heavily underclocked to the FSB change, 
you just pick another ratio for it that brings it closer to its stock 
frequency, or slightly above it.  Again, a good motherboard that has 
plenty of ratios to choose from helps immensely.

Of course today this isn't important anymore.  On my i5 CPU I can change 
the CPU multiplier.  Not that I do; performance is plenty right now 
without OCing.  I intend to overclock it in the future, just like I did 
with the C2D; if new games get more demanding, I'll do it then.