The TechReport benchmarked Phenom processors with TLB workaround:

Across every test we ran, the difference between the Phenom 9600 with and without the TLB patch averages out to 19.8%. However, if we rule out the synthetic memory tests and consider only the application tests, that difference drops to 13.9%.

The most troubling results here are the applications where we see large performance drops with the TLB erratum workaround active, including the Firefox web browser and the picCOLOR image analysis tool. If one happens to spend a lot of time running an application whose memory access patterns don't mix well with the TLB patch, the result could prove frustrating. The BIOS-based workaround for the TLB erratum may achieve its intended result-system stability—but it comes at a pretty steep price in terms of performance.

For the average retail PC consumer, this price might not be unacceptable. After seeing the Firefox test results, I spent some time browsing the web with our Phenom-based test system, and it didn't feel noticeably sluggish to me compared to most modern PCs. Then again, I doubt whether the average sort of consumer is likely to purchase a system with a quad-core processor. One wonders where that leaves AMD and the PC makers currently shipping Phenom-based PCs. I'm not sure a recall is in order, but a discount certainly might be. And folks need to know what they're getting into when purchasing a Phenom 9500 or 9600-based computer this holiday season. Caveat emptor, indeed