AMD Vishera FX-8350 Reviewformerstaff - October 22, 2012
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About this time last year AMD unveiled what was the highly anticipated and first significant CPU architecture change in over a decade. Big things were expected from this bold new architecture approach from AMD, if for no other reason than Bulldozer had seemingly been sitting in the oven for so long and the expectations by AMD itself was set very high with the PR campaign accompanying it. The result was a resounding thud as the first incarnation of the K15 architecture did not live up to the press slides promising things like 1.6x the performance of CPUs that had an 'i' in front of their titles.
The release of the second generation codenamed "Vishera" has seemed to be much quieter than the first. This time around there will be only be four Vishera SKUs released: the FX-8350, FX-8320, FX-6300, and FX-4300. The part we are concerned with today is the new flagship of the Vishera lineup, the FX-8350 or "Piledriver" CPU. AMD had promised from the open volley of the new architecture that was Bulldozer, there will be a 10-15% performance increase with each of the four new generations. With the release of Vishera, AMD has said that there are improvements to the IPC, power efficiency, frequency, as well as architecture changes we will get into a little further along.
So let's see how all of these changes to the second generation have fared compared to Bulldozer and the Intel competition it is aimed at. And speaking of who this new flagship is aimed at, AMD makes no bones about it being aimed squarely at the high end enthusiast. As I am one of those, let's see if it hit the mark.
Built on the same 32nm process as the previous generation, the FX-8350 is the enthusiast flagship of the Vishera offerings sporting the first ever 4.0GHz stock clocked CPU on the market. The FX-8350 is equipped with four Piledriver modules and eight cores in an 125W TDP. While the base clock speed is 4.0GHz, the Turbo will take this up to 4.2GHz when load dictates. The 315mm² die packs 1.2 billion transistors and an IMC that supports 1866MHz memory natively in dual channel mode. The FX-8350 has 8MB of L2 cache as well as 8MB of shared L3 cache
The chipset used for the Vishera is the same 990/970 used with the last generation. Good news for AMD fans in that your AM3+ 990FX motherboards will still provide a home for your new FX Vishera chip with only a BIOS update. The block diagram shows PCIE 2.0 lanes broken down as 2x16 or 4x8 +8x1+4x1 (2x1 on SB). Up to 14 USB ports are supported (up to four being USB 3.0) and six 6Gbps SATA ports and support for RAID configurations of 0, 1, 5, and 10. DDR3 officially supports up to 1866MHz of 1.5v, but supports up to 2400MHz (OC). I won't dwell on this too much as it's largely the same as the last release. So as a refresher course, here is a block diagram for your perusal.
AMD has made a number of improvements to the "Piledriver" cores it claims will add and enhance improvement to not only overall performance, but in the areas of IPC and operating frequency. Among them are a larger L1 TLB to improve virtual address translation speed, improved branch prediction, an improved HW data prefetch, and have improved upon the item that has been giving most of the blame for the slow single threaded performance of the last generation the FPU and INT scheduling. AMD has also claimed that it has made improvements to the efficiency of the shared L2 cache. The FX-8350 is identified as having C0 stepping as opposed to the FX-8150's B2 stepping. These and other improvements are adding up to some rather substantial improvements they claim.
Well some are saying that all this is a rework of the Piledriver core (module) some are saying it is nothing more than a stepping revision. The proof is in the numbers. So turn the page and have a look at the specifications and features, and then we will heat this chip up and see what it has to offer.