cpu speed question

[tim]

Thanks so much for your help on this. I have a lot to learn.
Okay, here's the link to the page of previous benchmarks for this cpu: http://www.mersenne.org/report_bench...ic_cpu=4377447

and here's the mprime benchmark output from mine. I'm not sure how to interpret it. Do I compare the "best time for" section to the benchmarks, or the "Timings for " section, looking at 4 cpus running 4 workers?
And for what's it's worth, under linux, the screen output for normal work for FFT 2M, pass1 256, pass2 8K (all 4 cores the same) was from 31 to 39 ms/iteration.
results.txt

Okay, more data. I've downloaded Intel Extreme Tuning Utility, and it shows TurboBoost is disabled. But it's enabled in the bios, and Win7 power setting is on High Performance. So I don't get it. And yes, it is enabled in the bios. Any ideas?

Another edit: I reset the bios to factory settings, and under Intel XTU, it now shows TurboBoost is enabled. No difference in performance, though. I did the prime95 torture test modes, the highest heat mode got the watts up to 63 and the heat to 159, the highest power consumption mode was 44 watts and 129 F, the same as normal operation.

[guru]

The system could be throttling way too soon. Check the heatsink and paste. Possibly upgrade the cooling of the CPU and case. Try running cpu-z while the system is loaded and monitor the top speed of the processor.

[tim]

It's not heat throttling. I notice that at idle the processor frequency is 3.692 Ghz, which is "turboboost" for this cpu. When I turn on Prime95, the processor frequency drops to 3.29 Ghz. When I stop it, the processor frequency rises to 3.692 Ghz. Shouldn't it stay high under full load? You can see that the temps are not excessive and there is no thermal throttling. And the CPU Total TDP doesn't go above 45 watts, when under full load it should be 80+ watts. Under Intel Extreme Tuning Utility CPU stress test, the frequency also drops to 3.46 Ghz and the watts range between 45 and 49, with the temperatures between 129 and 135 F. Here's a screen grab from Intel XTU of turning Prime95 off and on:

[tim]

Another piece of the puzzle: it IS hitting the current limit and throttling. Under Intel XTU, with full load, it shows Current Limit Throttling at 100%. With no load, it shows 0%. I think Current Limit Throttling occurs when the motherboard is sending current above specifications. Dell has replaced the motherboard (no effect) and sent a second, identical computer (no different). I've let them know about the current limit throttling, and that they need to either send a motherboard that doesn't cause throttling, or refund my purchase. Dell's support has been super, but I'm afraid my question won't reach someone with expertise to address this issue.

[tim]

To Dell's credit, they are going to RMA the computer and refund, even though it was sold by a third party, antonline.com through newegg. Excellent customer service from Dell, though.

It looks to me like the current limit throttling from the motherboard was designed by Dell to not run the CPU too hard to prevent wear/failure and prevent Dell service calls.

[guru]

Yep, typical Dell. Sell you something with high specs then run it under spec to prevent other flaws from showing. No matter how good Dell support is they will never make up for the inferior products Dell sells.

[guru]

Tim, did you get the replacement? How is it doing?