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To DDR3 or Not - AM3 Phenom II DDR3 Performance Drilldown

To DDR3 or Not - AM3 Phenom II DDR3 Performance Drilldown



DDR3 vs DDR2: Fight!

DDR3 vs DDR2: Fight!

By now, you may have heard rumblings about some new processors that have just been announced by AMD. If not, we advise you to check out our initial review of the first Phenom II chip and the recent debut of the AM3 Phenom II processors. These AM3 Phenom II processors are compatible with existing AM2+ motherboards (requiring a BIOS update in some cases) and will obviously work in an AM3 board, as the integrated memory controller supports both DDR2 and DDR3 memory.

Our review touched on the performance of the two lead Phenom II AM3-based models offered by AMD, the quad-core X4 810 and the triple-core X3 720 'Black Edition'. However, that review was conducted on a DDR2 platform to find out its immediate value proposition with lower cost DDR2 memory. Now that we have AM3 DDR3-capable motherboards in our lab, we'll be testing the performance of the Phenom II X4 810 on its native platform using an AM3 socket. Does the new platform lead to increased performance of the Phenom II? That's what we intend to find out.

Before we get to that, let us reiterate what we found from AMD about the DDR3 memory controller on the AM3 Phenom II processors. The official line is that the integrated memory controller on current AM3 Phenom II processors only support a single DDR3-1333 DIMM per channel, so one would likely be limited to 2 x 2GB modules for a total of 4GB memory as the typical configuration. Exceeding this limit would result in a lower memory frequency, i.e DDR3-1066.

Of course, while the official support for AM3 Phenom II is up to DDR3-1333, motherboard vendors have their own ways to 'overclock' this limit. The Gigabyte board that we used for testing, GA-MA790FXT-UD5P claims to be able to do DDR3-1600 and it certainly managed that as we found out:

You can expect other motherboard vendors to have similar, if not even more daring memory frequencies for their AM3 boards. This should come in useful for those with faster memory modules and are keen to overclock the processor/memory for more performance. For our testing today however, we'll be sticking to the official highest rated frequency of DDR3-1333 and looking at the performance differences (marginal if any) between that and DDR2-1066.

Test Setup

Obviously, we needed an AM3 board for our DDR3 testing and the first one that we managed to snag was Gigabyte's GA-MA790FXT-UD5P. This motherboard came with Gigabyte's proprietary Ultra Durable 3 technology which basically means that it has twice the amount of copper in the PCB. It is based on AMD's 790FX chipset but it's paired with the newer SB750 Southbridge. The rest of the test system for the Phenom II X4 810 on the DDR3 platform is as follows:-

  • Gigabyte GA-MA790FXT-UD5P (AMD 790FX + SB750)
  • 2 x 1GB Kingston HyperX DDR3-1333 (7-7-7-20)
  • Seagate Barracuda 7200.10 200GB SATA hard drive (one single NTFS partition)
  • ASUS GeForce 8800 GT 512MB (ForceWare 169.21)
  • Zotac GeForce GTX 260 (For World in Conflict and Crysis only, ForceWare 178.24)
  • Microsoft Windows XP Professional with Service Pack 2

We have reused our scores and CPU comparisons from the Phenom II AM3 article and if you need to refresh yourself, you can check out the test configurations here. Our usual set of benchmarks were used, though like we mentioned in the previous article, we had an issue where SPEC CPU2000 would not complete on the X4 810. The same occurred on the DDR3 platform, so till we have sorted this out, we have taken this benchmark out of the list, leaving us with:-

  • SYSmark 2007 Preview (ver 1.04)
  • Futuremark PCMark 2005 Pro
  • Lightwave 3D 7.5
  • 3ds Max8 (SP2)
  • Cinebench 10
  • XMpeg 5.0.3 (DivX 6.8 encoding)
  • Futuremark 3DMark06 v1.1
  • AquaMark3
  • World in Conflict v1.05
  • Crysis v1.1