AMD Fusion CPU bug
Problem:
Integer maths test and Prime number test give very low results. About 80% lower than expected. All other tests are give the expected benchmark results and you have an AMD Fusion Llano CPU.
Solution:
We believe this is related to a CPU bug.
At the time of writing this seems to effect about half of the AMD Fusion Llano CPUs when run in our CPU benchmark.
The bug itself can cause the CPU to hang or behave unpredictably while doing division operations. The workaround AMD suggested is to patch the CPU, which reduces the CPU performance to avoid the hang. The patch should be applied in BIOS. But only half the motherboard manufacturers have applied it from what we can see (as of April 2012).
AMD Fusion Llano CPUs include the A4-3300, A6-3500, A6-3600, A6-3650, A8-3800, A8-3850, Athlon II X4 641, AMD Athlon II X4 651 and a few others.
This problem will be reduced (slightly more hidden) in PerformanceTest version 8 where we will do less division.
For more details, see this post,
http://www.passmark.com/forum/showthread.php?t=3656
Problem:
Integer maths test and Prime number test give very low results. About 80% lower than expected. All other tests are give the expected benchmark results and you have an AMD Fusion Llano CPU.
Solution:
We believe this is related to a CPU bug.
At the time of writing this seems to effect about half of the AMD Fusion Llano CPUs when run in our CPU benchmark.
The bug itself can cause the CPU to hang or behave unpredictably while doing division operations. The workaround AMD suggested is to patch the CPU, which reduces the CPU performance to avoid the hang. The patch should be applied in BIOS. But only half the motherboard manufacturers have applied it from what we can see (as of April 2012).
AMD Fusion Llano CPUs include the A4-3300, A6-3500, A6-3600, A6-3650, A8-3800, A8-3850, Athlon II X4 641, AMD Athlon II X4 651 and a few others.
This problem will be reduced (slightly more hidden) in PerformanceTest version 8 where we will do less division.
For more details, see this post,
http://www.passmark.com/forum/showthread.php?t=3656
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