Last week, with the help of AMD, we brought you a list of motherboards that feature Phenom support and the ability to disable the TLB erratum fix. The fix is known to degrade performance substantially in some tasks, and we applauded AMD's decision to disclose which motherboards could work around it.
Right now, the Phenom motherboard situation must be tracked on a case-by-case basis, but AMD has informed us unequivocally of a very big upcoming change: "There will be BIOS drops in the coming weeks by all motherboard vendors that also put a switch in the BIOS to bypass the TLB erratum fix." We consider this the most optimal outcome—putting control in the hands of the user and eliminating any ambiguity about it.
Unfortunately, one must deal with the situation carefully until those BIOSes arrive, and the list we published last week apparently included some errors. The data AMD gave us didn't distinguish between motherboards that could disable the erratum fix via the company's OverDrive utility and those that could disable it via a BIOS option, and it indicated that a number of motherboards based on AMD 690-series chipsets could disable the TLB fix. We later discovered that OverDrive doesn't actually support 690 chipsets. Dubious that all those boards had BIOS workarounds in place, we expressed our concerns to AMD. The chipmaker subsequently confirmed that most 690G boards do not in fact have any option to turn off the workaround yet. The 690G motherboards without a way to disable the fix at present include:
- Asus M2A-VM
- Asus M2A-MX
- Biostar A690G M2+
- ECS AMD690VM-M2
- ECS AMD690GM-M2
- Foxconn A6VMX/A6VMX-K
- MSI K9AG Neo2-Digital (MS-7368)
- MSI K9AGM3-FIH (MS-7367)
- MSI K9AGM4-F (MS-7373)
We have updated the table in our original news item to reflect this information. Currently, Gigabyte's 690G-based GA-MA69G-S3H and GA-MA69GM-S2H mobos are the only ones with a BIOS-based workaround for the TLB fix in place—at least, until those new BIOSes become available.