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Take a look at this. (i7 TLB bug)

Posted: Mon Dec 01, 2008 2:49 pm
by rudis
We were told that Intel's Nehalem, the CPU that we know as Core i7 has TLB. TLB, three letters that have destroyed the sales of Phenom and Opterons based on 65nm K10 cores, stands for Translation Lookaside Buffer, and Intel officialy states in its Intel Core i7 Processor, Extreme Edition Series and Intel Core i7 Processor - Specification Update PDF, that the CPU has a TLB bug.

If you open Intel’s official document that is nicely stored here, on page 37 AAJ1 Clarification of TRANSLATION LOOKASIDE BUFFERS (TLBS) Invalidation part, you will see that Intel says that in some rare cases improper TLB invalidation may result in unpredictable system behavior and can hang your OS or result with incorrect data. Here is the word to word quote: "In rare instances, improper TLB invalidation may result in unpredictable system behavior, such as system hangs or incorrect data. Developers of operating systems should take this documentation into account when designing TLB invalidation algorithms. For the processors affected, Intel has provided a recommended update to system and BIOS vendors to incorporate into their BIOS to resolve this issue."

We are not sure if you should be concerned, but such a thing completely destroyed K10’s reputation and we will certainly do a bit more investigating about it, and ask Intel for a comment. We would like to thank one of our readers for the tip.
Source:

http://www.fudzilla.com/index.php?optio ... 7&Itemid=1

Re: Take a look at this. (i7 TLB bug)

Posted: Mon Dec 01, 2008 3:14 pm
by GI-JOE
Deja vu? :mrgreen:

Re: Take a look at this. (i7 TLB bug)

Posted: Mon Dec 01, 2008 3:19 pm
by DX
I wonder just how rare the problem is. It can't be very bad as I would have thought that all those reviews would have indicated a problem already after running all those benches.

Re: Take a look at this. (i7 TLB bug)

Posted: Mon Dec 01, 2008 3:25 pm
by Apoptosis
Every processor has hundreds of bugs that are known about or found during its lifespan. Intel obviously knew about this issue before the chip was introduced into the wild and it doesn't seem to be a deal breaker by any means. AMD's TLB issue was found not by them, but a customer that was running intense applications in VMware. The only fix to it was a BIOS patch that killed performance, but the CPU went through a stepping revision that took care of the problem without a significant performance hit.

I've pinged intel on this, but this is just fud

Re: Take a look at this. (i7 TLB bug)

Posted: Mon Dec 01, 2008 4:33 pm
by Apoptosis
here is an official response from Intel to Legit Reviews:
The “AAJ1 Clarification of TRANSLATION LOOKASIDE BUFFERS” document is a SPEC CLARIFICATION, and is simply a pointer to a previous document written in April 2007.

SPEC CLARIFICATION AAJ1 was initially added due to an issue on the Intel® Core 2 Duo processor which was previously corrected with a BIOS update; this issue does not impact the Nehalem Family of CPUs. There are errata on the Intel® Core i7 processor that relate to the TLB. These all relate to improper translations or error reporting, and all of those that impact functionality have been fixed via BIOS updates prior to Core i7 launch.

Re: Take a look at this. (i7 TLB bug)

Posted: Tue Dec 02, 2008 10:34 am
by rudis
Thanks for the clearing up. I also thought that it was quite strange that none of the initial reviewers didn't stumble upon anything like this. So it's no "told-ya-so" and "let us not be hasty" for the lucky few with X58's.

Re: Take a look at this. (i7 TLB bug)

Posted: Fri Dec 19, 2008 4:45 am
by hercules71185
I haven't got my gpu yet. Nor can I fully assemble my pc till Christmas.. I'm whipped... BUT, I did a build for an i7 with the gtx 260 instead of my 280 is the only difference and I don't care what bug it has. That thing doesn't stutter in anything. I only had pcmark05 to test his on and it was over 11000 even without having a high overclock yet. The last 8600 wolfdale I built bearely cleared 9k @ 4.1.