discussion forum


message

Name: king
eMail: the__king76@hotmail.com
Date: February 13, 2001 at 16:24:13
Subject: Re: Some questions (CPUID)....
In Reply To: Re: Some questions (CPUID).... by
Christian Ludloff on February 13, 2001 at 13:16:45
Text: || pre-B0 step pentiums supply "weird" results when calling standard level 0.
|| how do i get the maximum supported standard level? is it the value
|| in register al?
|
| The pre-B0 step Pentium does not support multiple CPUID levels: no matter
| what input value you supply in EAX, all CPUID does on those processors is
| load the family/model/stepping values into bits 11-8/7-4/3-0 of EAX.
|
| So if you execute CPUID with EAX=0, and get EAX=0000_05xxh, then you know
| it's a pre-B0 step Pentium.
|
| You will have to "assume" 0000_00FFh for the standard feature flags: this
| puppy supported FPU/VME/DE/PSE/TSC/MSR/PAE/MCE/CX8. (Yes, though somewhat
| broken, it did have PAE support.)
|
|| are the values returned by standard level 2 (cache) really standard for
|| amd/intel or should i use standard level 2 for intel only (to retrieve the
|| l1/l2 cache) and extended level 5/6 (to retrieve the l1/l2 cache) for amd?
|
| The descriptors returned by level 0000_0002h are vendor-specific. (If you
| check the sandpile.org's CPUID page, then you'll notice that (a) only In-
| tel and Cyrix processors support them, (b) they are mostly for Intel pro-
| cessors, and (c) Cyrix' descriptors collide with Intel's.)
|
| By contrast levels 8000_0005h and 8000_0006h are more flexible -- various
| AMD, Centaur, and Transmeta processors support them.
|
| So far there is no processor which supports both.
|
|| is that correct?
|| - amd-k6-2+ = l2 cache 128kb and amd-k6-III+ = l2 cache 256kb?
|
| Yes.
|
|| - family 15, model 0 = pentium 4 (willamette)? no other models?
|
| If the family is Fh, then you must check the new extended family field.
| If the extended family is 00h, then it's a Pentium 4.
|
| Does anyone have access to a Foster (ie. P4 Xeon)? If so, then please let
| us know its model (0h or 1h?) and its extended family (01h?). :-)
|
| --
| CL
|

thanks for the info!


post a followup message
(Be nice... or be blocked. Be technical... or be erased.)

Name: optional link title:
eMail: optional link URL:
Subject: optional image URL:
  Insert line breaks by hand when only about one inch remains at the right side. Otherwise your message will be unreadable.
Text:
 

  Note: The above eMail form fields may look unaligned if you are using a browser other than Netscape Navigator version 3.0.


currently posted followup messages
(You may have to press the RELOAD button of your browser.)


main page