AMD FX-8350 Vishera 8-Core CPU Review
Vital Signs and Overclocking
The new AMD FX-8350 uses the same packaging and socket as previous-generation FX-series processors, based on the Bulldozer microarchitecture. As such, save for some markings atop the chip’s integrated heat-spreader, the new AMD FX-8350 looks just like its predecessor.
As we’ve already mentioned though, the main differences between the new FX-series and the previous gen, are the new processor’s updated Piledriver microarchitecture, which offers a number of performance and efficiency enhancements over Bulldozer, and the new processor’s more advanced 32nm manufacturing process.
Here is an up-close-and-personal look at the FX-8350 as reported by the latest version of CPU-Z. As you can see, the FX-8350 uses AMD’s existing AM3+ socket infrastructure. If you remember, socket AM3+ was an update to the older socket AM3, and although pin-compatible, AM3+ adds support for CPU voltage loadline, increased ILDT current for higher frequency HyperTransport links, increased DRAM current, and two memory channels with official support for speeds of up to DDR3-1866. All of these features are exploited on the AMD FX-8350.
As you can see in the images above, the AMD FX-8350 has 128K of L1 data cache (16K per core), 256K of L2 instruction cache (64K shared across each dual-core module), 1024K of L2 cache per core, and a total of 8MB od shared L3 cache. The FX-8350 uses the same 200MHz base clock as previous generation FX-series processors as well; it’s peak 4.2GHz Turbo frequency is derived by using a 21x multiplier and the default 200MHz base clock. Note that the chip runs at about 1.4v when hitting max Turbo. Cool ‘n Quiet is also present on the latest FX, however. When idling, the chip clocks down to 1.4GHz at only .9v.
We were present when the original FX was overclocked to over 8GHz, achieving a Guinness Book World Record in the process. Since its predecessor was such an adept overclocked, we were eager to see what the new FX-8350 could do. To that end, we also spent some time overclocking the new AMD FX-8350 processor, using a standard air cooler and the UEFI overclocking options available on the Asus CrossHair V Formula. For these overclocking tests, we bumped the CPU voltage up to 1.4125v, disabled Turbo, and increased the CPU's multiplier until our test system was no longer stable.
In the end, we were able to take the FX-8350 up to a stable 4.7GHz. Unfortunately, due to time constraints and an incompatibility with AMD OverDrive and our test-bed’s motherboard, we don’t have accurate temperature data to share at this point. But considering how easy it was to take our CPU to 4.7GHz, we suspect that higher clocks will easily be possible with more exotic cooling and more aggressive voltage tweaking.
As an interesting aside, overclocking the FX-8350 to 4.7GHz resulted in a Cinebench R11.5 score of 7.94, and increase of 1.01 or 14.5% over the stock score of 6.93, and enough of a boost to overtake the Core i7-3770K.