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B2 Stepping - TLB Bug Is Still Around

AMD Phenom 9600 Black Edition: New Hope?
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In November of last year, AMD introduced the Phenom CPU, its first quad-core processor. The 2.4 GHz model was meant to launch as the flagship, but the chipmaker had to cancel it at the very last minute, due to a bug in the Translation Lookaside Buffer (TLB). Due to this error, there is an increased chance that the Phenom may crash the system under very rare and unusual circumstances. This may occur when lines of code are transformed into physical addresses in the L3 cache, while there is simultaneously a large amount of data traffic. To put your mind at ease, let us say at this point that this is a scenario that does not occur with normal desktop applications. Also, we didn't encounter this phenomenon during any of our tests. Nonetheless, AMD decided to play it safe and not sell any Phenom processors running faster than 2.30 GHz.

The Phenom 9600 Black Edition continues to use this faulty B2 stepping, which we can't really understand given that AMD sells this CPU specifically as an overclocking part. Currently, there are three Phenom models, all of which use the B2 stepping.

Overview of Phenom Models
Model Stepping Availability
Phenom 9900 B3 June 2008
Phenom 9700 B3 April 2008
Phenom 9600 BE B2 now
Phenom 9600 B2 now
Phenom 9500 B2 now

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  • 0 Hide
    ShadowKai , July 6, 2008 5:34 AM
    I think on page 14 the author meant:

    "When Cool'n'Quiet is deactivated, idle power consumption rises to 51 watts. The jump in power consumption at 2.70 GHz is a direct result of the core voltage increase from 1.250 V to 1.400 V."

    And the bars for Phenom 9600 BE and Phenom 9600 BE (CnC) should be switched around.
  • 0 Hide
    Anonymous , October 2, 2008 6:34 AM
    I think it's also important to mention the fact that Vista SP1 includes it's OWN TLB fix which overrides the bios setting of many boards. I used an app that works in conjunction with Crystal CPUID to change the MSR directly to deactivate this secondary TLB fix. It caused a dramatic improvement in performance; the quick and simple WinRAR bench went from 232 to ~1300 after the fix. Just think it's worth mentioning!
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    Anonymous , November 30, 2011 9:48 AM
    I think I may have found a new problem with this bug. I have a Phenom X4 9600, and have tried two different motherboards. The problem occurs when running Windows 7. BSOD with a message stating that the operating system did not receive an clock interupt signal from the second processor. At first I thought it was a bios problem, but have since had to replace the motherboard. Tried Windows 7 again after replacing the motherboard and still having the same problem.