CPU Overclocking: Improvements?
The CPU does overclock better, you'll be glad to hear, although not much more on the current 965 Black Edition. We managed to squeeze out a solid 4GHz at 1.5V by increasing the multiplier, which we used in the next few pages benchmarking. Unfortunately, 4.1GHz just wasn't quite stable enough and an increase in voltage greatly increased temperature causing overheating on our Noctua heatsink. We also tried other heatsinks and additional fans, but to no avail.
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The HyperTransport bus was considerably tweakable though, and while keeping the overall bus within a light overclock, we found it would increase all the way to 325MHz, stable, before we lost one of the DIMMs, but still the system would boot up until 380MHz. The overall available HyperTransport frequency was not notably increased from the C3 965 Black Edition though.
Memory Overclocking: Improvements?
AMD has put sufficient effort into its integrated memory controller, where previously we could normally achieve 2.4 to 2.6GHz, depending on the chip and motherboard, the C3 965 Black Edition easily ramped up to 2.8GHz.
Trying for a round 3GHz left the system requiring a complete CMOS reset, and weirdly saved BIOS profiles would not work - we had to gently re-overclock little by little. This maybe a quirk with the motherboard though.
As far as overall DDR3 frequency goes, we didn't find much of an improvement, as our modules topped out at just 1,740MHz.
- Motherboard: Gigabyte GA-MA790FXT-UD5P
- Memory: 4GB G.Skill Pi-Series 1,600MHz, CL7
- Graphics card: Zotac GeForce GTX 280 (with ForceWare 185.68)
- Cooler: Noctua NH-C12P modded with larger fan
- Hard disk: 160Gb Seagate Barracuda 7200.9
- Power Supply: PC Power and Cooling Silencer 750W
- Southbridge driver: Catalyst SB 9.4
- Operating System: Windows Vista Ultimate 64-bit, SP1