On Thu, Jan 12, 2006 at 04:38:50PM -0500, Homer Whittaker wrote: > I have searched thru the various tech notes and papers specified below > but am unable to find out HOWTO pick up the BIOS setting that are > referenced in your posts. > Can you be definitive in the exact settings (and where) for the AMD > Athlon 64 Socket 754 version?
Are you asking how to set your BIOS to run at DDR400 (actually 200MHz, but with two data transfers per clock, so ddr400) or DDR333 (166MHz), or whatever? Some BIOSes have a setting for that directly, while in others you don't specify the absolute memory speed, but rather at a ratio of some other clock. e.g. in this old review of the K8V Deluxe http://www.lostcircuits.com/motherboard/asus_k8v/7.shtml, they say the BIOS had an Memclock to CPU Ratio setting. The BIOS will usually print out somewhere what speed your RAM is running at, either in MHz or DDRsomething. Probably more recent BIOS versions would present it as DDR something and hide the ratio stuff from the user. You can always boot memtest86+, and it will show you DDRsomething, and your memory timings (e.g. 3-4-4-7 = CAS latency: 3, etc. I don't remember which order they're in. see http://www.tomshardware.com/2006/01/04/bios_from_a_to_z/page11.html) Then you can poke at settings until you get something that makes memtest or the BIOS show you the speed you were aiming for. On my Asus K8V, the BIOS has a memory clock option, and if I take it off auto, I can set it to DDR333, which is what I do, because I have two double-sided DIMMs, in slots 1 and 3. At first I thought you were asking exactly where I found what speeds were ok, so I'll answer that, too: In AMD's doc http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/26094.PDF the table for socket 754 CPUs using unbuffered DIMMs is on pages 175-176. I guess x8 double rank = double sided, while x8 single rank or x16 means single sided memory modules. Earlier pages go into a lot of detail about timings (e.g. CAS latency), and tradeoffs vs. clock speed. e.g. the BIOS should go on memclock step slower if that lets it go one whole CAS latency faster. e.g. prefer DDR333 CAS 2 to DDR400 CAS 3, but not DDR333 CAS 2.5. (The docs says that tidbit of info was based on performance testing.) If none of that makes any sense, you should look on hardware review sites like tomshardware or anandtech for some bios settings guides. Or you should accept the fact that electronics are complicated, and just use AMD's table of settings as best you can without spending huge amounts of time learning electronics. -- #define X(x,y) x##y Peter Cordes ; e-mail: X([EMAIL PROTECTED] , des.ca) "The gods confound the man who first found out how to distinguish the hours! Confound him, too, who in this place set up a sundial, to cut and hack my day so wretchedly into small pieces!" -- Plautus, 200 BC -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]