Originally Posted by campb292
I have gotten it up and stable just over 4ghz with 475 fsb and 1800 DDR3 at 7-7-7-20. It passed 4 hours of OCCT on large, 10 hours of P95 on blend, memtest86+ for 4 passes. I could not run the IBT on it, as I started it and canceled it as temps were inching their way up in the mid-70s. I booted up an old OC just to check it out (450fsb, like 3.8ghz) and passed a 5 5 and 10 runs. Dude... that program is outragous. On OCCT large I never get over 60-62 on any core over an hour. IBT on that 3.8 overclock hits 68 on the first run and the other 4 all slam into the mid-70s... almost 15c higher. That program is whacked.
QUESTION OF THE DAY:
Let's say machine A passes memtest86+ over 6 passes. Machine A passes 12 hours of P95 small FFT. Machine A fails OCCT large after 1 hour and 20 minutes. Does the fact that is passes memtest mean the memory and the mch are volted correctly? Does memtest test the memory and memory hub (northbridge)?
I don't know the answer to the last question, however, based on what I've been taught, proper testing of memory should be done by doing several hours of the Blend test and then approximately 10 passes in Memtest (or in the opposite order). One cannot call the memory stable and error-free until it passes both several hours of the Blend test for stability checking and then Memtest for error checking. The Small FFTs test is only for CPU stress-testing in order to check for stability, so it is not a test that is used when an overclocker is focusing on their memory.
Regarding the Linpack test (see my sig), it is most definitely not "whacked". It's probably the best stress-testing tool available right now. It makes the CPU do much more complex calculations than the Small FFTs stress test. This is why the temps are 10-15Â°C higher. However, don't worry about it. It's not like you're making it go that high 24/7 every single day for 6 months straight. It's just a couple of hours, so it's harmless.
Furthermore, the Large FFTs test is not a CPU-only stress test, so it's actually inappropriate to compare the Large FFTs to a Linpack test.
Originally Posted by campb292
I am curious what temps you feel are too high. I was under the impression, both from this forum and intel specs, that 60-62C under heavy stress testing load (OCCT or P95) are perfectly fine temps for a 4ghz overclock. The only temps I have that are mid-70 are produced by Intel Burn Test, but that really seems irrelevant as it typically isn't even used to determine stability on an overclock that is so high.
Aside from the OCCT and P95 60-62C max I get, my common use/idle temps are in the low 30's and gaming temps are in the 40's. Intel's thermal spec is listed as 71 degrees for the 9550.
The Thermal Specification isn't talking about the core temp, it's actually talking about the temperature on the surface of the chip (where dust would land on the integrated heat spreader of the CPU if it were just sitting on a desk). Here's what you see if you click on Thermal Specification:
Thermal Specification: The thermal specification shown is the maximum case temperature at the maximum Thermal Design Power (TDP) value for that processor. It is measured at the geometric center on the topside of the processor integrated heat spreader. For processors without integrated heat spreaders such as mobile processors, the thermal specification is referred to as the junction temperature (Tj). The maximum junction temperature is defined by an activation of the processor IntelÂ® Thermal Monitor. The Intel Thermal Monitorâ€™s automatic mode is used to indicate that the maximum TJ has been reached.
And here's the explanation of TDP:
Thermal Design Power: (Also referred to as Thermal Guideline) The maximum amount of heat which a thermal solution must be able to dissipate from the processor so that the processor will operate under normal operating conditions.
So, as you increase the core voltage, you simultaneously increase the TDP which also simultaneously decreases
the Thermal Specification. But if the temperature is at 71Â°C at the "geometric center on the topside of the processor integrated heat spreader", then how hot are the cores?
But this uncertainty may be why people say that, as a general rule, try to keep load temps under 70 for an overclock. But this may also have been taken from the average Thermal Specifcation listed for all of Intel's processors. Besides, a CPU will shut itself off if it gets too hot in order to protect itself.
So, I say do this: Run a Small FFTs stress test and get it to be stable at 12 hours with your temps averaging no more than like 70. If it's stable after about 12 hours, then run LinX for like 30-50 times (and use the largest "Problem size" that it will allow you to use, or rather, click on "All" for "Memory to use". This will be superior to the Linpack test in OCCT (and probably IBT too). 30 times may take up to an hour, to an hour and a half. But, it's said that 20-30 passes of Linpack at 100% stable is almost an equivalent of 12 hours of Small FFTs, except that the Small FFTs is a different test, so Linpack cannot replace it.
So, to summarize, use the Small FFTs (or for OCCT, the Small Data Set) and the Linpack for CPU stress testing, and then Blend (or Medium Data Set) and Memtest for memory stress testing/error checking (respectively). I don't know what good a Large FFTs stress test does, however, OCCT says that the Large Data Set stresses the CPU/Chipset/Memory chain with huge data transfers. But I have never seen anyone on Overclock.net recommend it (and I've actually been around since late January/early February of 2008).
And for temps, I say go with the temps you get from a Small FFTs stress test since this is the most common right now. I mean, when people say what their load temps are, almost everyone is going to assume that they mean the Small FFTs test.
And of course, your temps will be fairly high with a big overclock like that. If I were to overclock my CPU by that much, I'm sure my Linpack temps would go into the 70's too.
Anyway, that's pretty much all I have. And by the way, I apologize for my reply. I feel a little "off" today. hehe