Samples of AMD’s long awaited B3 stepping quad-core Opteron finally made its way to system integrators earlier this month, fixing the translation lookaside buffer (TLB) erratum that caused the company to stop shipments of the server chip late last year. Phenoms affected by the erratum, however, continued to ship together with a BIOS fix – though the workaround supposedly hampered performance considerably in some tasks.

Well, the folks at AnandTech have managed to get their hands on a 2.2GHz engineering sample B3 stepping Phenom and ran a few tests against a B2 stepping Phenom 9600 to get an idea of how much of a performance hit the BIOS TLB fix incurs. The highest performance impact was on a WinRAR benchmark, with a drop of over 70 percent. The results show the B3 Phenom actually performing slightly better than the B2 chip with the fix disabled (1357KB/s versus 1348KB/s), while the B2 chip with the BIOS fix enabled scored a meager 365KB/s. Check out the complete report here.