Setup:
Processor | Core i7 875K |4 Core 8 Threads| 2.93ghz | 8mb cache| Socket LGA1156 | SLBS2 | Batch# L004B840
Mobo | EVGA P55 200 Classified Motherboard
Corsair GTX1 | 2GB | 2400mhz | 9-11-9-27 | 1.65v | ver8.1 | 2 sticks
PSU | Silverstone 1500w
OS | xp (lite)
Cooling | Dragon F1 EE + Ln2
Benchmarks | 2D stuff
Click and browse thru the benches:
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Quick Session: I was bored with the dancing Storm Troopers on the MSI MOA 2010 Livestream so I decided to see what this Intel 875K chip was about and started a really quick bench session.
Cold Bug: -120c
Cold Boot Bug: On Hard Lock it was mostly a -60c Cold Boot Bug. But, on occasion the cbb moved to -85c and -105c.
X-Cool/Xtreme Cooling: the x-cool jumper and xtreme cooling modes on the EVGA P55 motherboard do not appear to be suited for this particular K-series chip. Stability was worst at higher clocks and the board exhibited signs of cold issues past -100c with the x-cool jumpered. The best results were had with x-cool not jumpered and Xtreme cooling modes disabled. EVGA may be able to improve this function with a bios update but as for now it doesnt appear as a useful feature on this chip.
Vcore Voltage: This particular chip did not enjoy any voltage above 1.478 Vcc no matter how cold. There doesnt appear to be much scaling above 1.43vCore.
Vtt: best results were at 1.275 vtt, upwards did not help stability at higher clocks
PCH: 1.475 gets the job done while 1.35 was hit or miss.
vDimm: 1.70 thru 1.73 allowed for the chip to behave in wprime and made no difference in pi at the upper end clocks shown above.
Signals: All signals were maxed -31
Multiipliers: This chip has an unlocked multiplier but so far it appears to be next to useless. 26 worked well and so did 25, but 27 thru 30 were rubbish.
K-Boost: I didn't play around too much with the K-Boost feature available in the bios for K-Series chips but what it does is auto set the multi to 27. Any monkey can do that.
Boot up: I found the most stability booting in at around 170x26=4420mhz 1.45vcc 1.275 vtt 1.70 vDimm @ -60c (increase clocks voltages in OS as needed)
Scaling: This chip scaled with voltage for the most part not cold. At -60c and 1.43vcc I was able to blck all the way up to 195 without touching the voltage on the first boot. It was wprime capable thru 195 bclck as I poured down to -85c towards the end.
Fine Tuning: I tested a number of singalling, timings, sub-timings, qpi settings and voltages settings. It appears that the lowest QPI setting w/mch strap to dram/ratio was the most effective/functional setup.
Thats it for my quick summary regarding the Intel 875K chip. Thank you for reading
