From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.gentoo.org (woodpecker.gentoo.org [140.211.166.183]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by finch.gentoo.org (Postfix) with ESMTPS id AF1681582EF for ; Tue, 18 Feb 2025 21:19:22 +0000 (UTC) Received: from lists.gentoo.org (bobolink.gentoo.org [140.211.166.189]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) (Authenticated sender: relay-lists.gentoo.org@gentoo.org) by smtp.gentoo.org (Postfix) with ESMTPSA id 9998D34319F for ; Tue, 18 Feb 2025 21:19:22 +0000 (UTC) Received: from bobolink.gentoo.org (localhost [127.0.0.1]) by bobolink.gentoo.org (Postfix) with ESMTP id E8A9411047E; Tue, 18 Feb 2025 21:18:11 +0000 (UTC) Received: from ciao.gmane.io (ciao.gmane.io [116.202.254.214]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (prime256v1) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by bobolink.gentoo.org (Postfix) with ESMTPS id D689B110470 for ; Tue, 18 Feb 2025 21:18:10 +0000 (UTC) Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1tkUyl-0002a8-J0 for gentoo-user@lists.gentoo.org; Tue, 18 Feb 2025 22:18:07 +0100 X-Injected-Via-Gmane: http://gmane.org/ To: gentoo-user@lists.gentoo.org From: Grant Edwards Subject: [gentoo-user] Re: problem formatting new 256 GB USB stick : alternatives Date: Tue, 18 Feb 2025 21:18:03 -0000 (UTC) Message-ID: References: <115993398.nniJfEyVGO@rogueboard> Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org X-Auto-Response-Suppress: DR, RN, NRN, OOF, AutoReply Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit User-Agent: slrn/1.0.3 (Linux) X-Archives-Salt: 481e1f3d-a622-48b0-9652-cda332e1610b X-Archives-Hash: 501473d461d890cdafcb31757279b729 On 2025-02-18, Philip Webb wrote: > 250218 Frank Steinmetzger wrote: >> I recommend an external USB case with an NVMe SSD inside. >> This may not be as compact and not as cheap, >> but they are much much much faster and probably longer-lasting >> than any USB stick, because their flash controllers are more sophisticated >> and the parts of higher fidelity. A not-too-cheap NVMe will do fine, >> as long as it’s TLC, not QLC flash. > > Can you explain this -- TLC/QLC -- in more detail ? Tri-Level Cells, Quad-Level Cells. SLC (single-level cells) Each "cell" consists of a capacitor (constructed as a FET with an isolated-gate). In the old days, the capacitor was either chared or not: two levels. One bit per cell. Easy to make and reliable. If you want more bits, layout more cells. That means larger dies, which means more money. MLC (two-level cells) OK, let's also do four different charge levels! You get _two_ bits per cell with the same area of silicon. Harder to do and not quite as reliable, so we'll add a few extra blocks of cells and make software deal with blocks that don't work. TLC (tri-level cells) Hey, what if we do 8 different charge levels! Now you get 4 bits per cell. Even harder to do, even less reliable... QLC (quad-level cells) [I think you see where this is going]