Voltage versus MHz
We all know that higher voltage means higher clock frequencies, so in order to give you a view on what you can expect using higher voltages; we attached the Mach2 cooling system onto the CPU and slightly increased the vcore.
The 45nm chips are known for their high overclocks, even on stock voltage. 4Ghz isn't that special anymore and if you're really lucky, you might be able to run 4,4Ghz on plain air cooling. The most limiting factor when overclocking is without doubt the motherboard, to be more specific, the chipset and the bios.
This reminds me of the early Conroe motherboards as we had to wait a few months to have high FSB frequencies as the first chipset that was capable of running high FSB's was the 965. The latest chipset are not ready to take the 45nm chips beyond 600+ FSB and most of the boards will be stuck at 550MHz FSB or less on air cooling. The P35/X38's all have the same issues, so the only solution is a newer chipset or better support for the Wolfdale and Yorkfields. However, something strange occured when reading about this issue and talking to people who tried to bypass these problems. It seems that one of the older chipsets, the 965, have no problem at all reaching 620MHz FSB on air cooling
! So in order to max out your CPU, you'll have to find a P5B or Commando. On air, however, every motherboard will do well.
Regarding the bios, we have some things to tell as well. Please use the newest version of the bios, even if it's already have support for the 45nm Wolfdale. It seems that the overclockability increases when using newer bioses, for instance:Max FSB on the DFI LP UT P35:
1) Bios 1224: 545Mhz
2) Bios 0109: 585Mhz
However, it seems that some biosses -that don't support 45nm- produce insanely fast SuperPi 1M times. Best thing you can do is try out the best bios for performance and FSB.LN² overclocking
We asked and were allowed to drop this CPU under ln² and see what it was capable of. Using the DFI LP UT P35 and some OCZ PC2-9200 memory, we managed to get some very decent results.5th
E8500 CPU-Z in the world
PiFast in the world23rd
Superpi 1M in the world14th
Superpi 32M in the world
All in all, Blind and me got some very decent results considering the untweaked OS and the slower memory. Note that we currently hold the best scores in Belgium and please stay tuned for more as we'll try to get our hands on an 965 motherboard. The CPU is one of the best Wolfdales I've seen as a voltage of 1,75-1,8v is enough to max out the setup (being bottlenecked by the chipset).
Please check out our threads at numerous overclocking forums to find more information and pictures:OCXtreme