Hi everybody. Thanks for this thread, very informative. Below is my story with the 875K so far.
I used to have an i7 860 but after reading reviews, forums and considering the ability to customize Turbo ratios, I couldn't resist and bought an 875K. Actually, not just 1 but 3: found them at "attractive" prices and had the money so I wanted to try all 3 and keep the best out of the bunch.
Compared to my 860, my 875K runs a lot cooler at the same frequencies, despite the voltage difference (see my signature for system specifications and cooling equipment):
- i7 860: Prime95 stable at 4GHz (20 x 200 w/ HT) - VCore: 1.375V - Load temperature: 82Â°C.
- i7 875K: Prime95 stable at 4GHz (30 x 133* w/ HT) - VCore: 1.4V - Load temperature: 75Â°C.
* Same stability and temperatures at 25 x 160, 24 x 166.67 and 20 x 200.
I was pleasantly surprised at the temperature difference. That's what I was hoping for as I always found my 860 to run abnormally hot (tried reseating the waterblock with a thinner layer of Arctic Cooling MX-2, no difference -- but I'm haven't given up on it yet) and it definitely wasn't because of my WC loop given that the temperatures of my HD 5850 in that same loop are excellent (35Â°C at idle, 40Â°C under FurMark at 1920x1080 in extreme-burning mode).
The maximum stable frequency of the 875K is disappointing though. I can't get it stable over 4GHz, not even 31 x 133. Tried every combination of BCLK / CPU ratio / Turbo ratios / spread spectrum toggles / overheating protection, went as high as 1.5V of VCore. But it always ends up crashing under Prime95 (Large FFT), even at just 31 x 133 with 1 core active (custom Turbo at +0+0+0+1). However, it did boot into Windows up to 4.4GHz (33 x 133) on all cores.
This first 875K has the following FPO/Batch#: L012B159. I received the other two in the mail yesterday. Both are L012B141, will try one of those this evening or tomorrow evening. Hopefully they will be better chips than this one.Edited by Roman2K - 7/6/10 at 4:37am