Overclocking Core i7-3930K
Now, you don’t swap out a $300 motherboard for a $225 platform and expect the same experience, so I initially tempered my expectations of overclocking on ASRock’s X79 Extreme4-M.
That was premature, though. Using the company’s latest firmware, I had no trouble booting up at 4.4, then 4.5, 4.6, and finally 4.7 GHz. Those last two frequencies were fine for benchmarking, but they gave out under IntelBurnTest, compelling me to settle in at a modest 4.5 GHz.
I could have gone higher. The chip’s power consumption crested at 183 W at 1.375 V, and ASRock indicated to me that its board should take 200 W or so. Given a 91°C ceiling and temperatures that topped out around 80°, thermals weren’t the problem. The Core i7-3930K wanted more voltage. But even the settings I used aren’t guaranteed to be safe over the long term, so it wasn’t worth it to me to nudge up to 1.4 V.

With all of that said, 4.5 GHz was rock-solid down at 1.361 V, so long as the most important variable was controlled: cooling. I used Intel’s RTS2011LC for my processor, which left the X79 Extreme4-M’s VRM vulnerable. Naturally, instability ran rampant even at lower power levels. Simply adding a fan blowing over the motherboard solved all heat-related issues.
As a general rule of thumb, it’s possible to get great clock rates from the Sandy Bridge-E-based chips we’ve tested, so long as you’re willing to put plenty of voltage through them and throw big cooling at the resulting heat. We’ve talked to system builders willing to go 4.4 GHz on shipping machines, so our 4.5 GHz overclock on a retail-purchased processor turns out to be pretty solid.
Overclocking Core i7-3820
The Core i7-3820 hits respectable frequencies as easily, but it requires a slightly different approach. Because it’s neither an X- nor a K-series SKU, the -3820 is constrained by “limited overclocking.” In short, it scales up to six 100 MHz bins beyond its maximum Turbo Boost clocks. With three or four cores active, it hits 4.3 GHz. When one or two cores are busy, it jumps to 4.4 GHz.
That leaves performance on the table, though, making it necessary to exploit the strap ratios incorporated into the X79 Express platform. ASRock’s X79 Extreme4-M doesn’t expose them explicitly, though we’ve asked the company to add the ratios, and it now plans to. However, manually specifying 125 MHz, for example, allows the PCI Express and DMI buses to remain within spec.

Interestingly, our -3820 didn’t want to run at 4.5 GHz, but it worked at 4.625 and 4.75 GHz using 37x and 38x multipliers. Still finicky, it wouldn’t complete the entire benchmark suite, even with a longevity-unfriendly 1.44 V driving it. But my expectations for this one weren’t high anyway. And if you need a quad-core chip, I don’t see any reason to buy a high-end platform (X79), quad-channel memory kit, and a locked processor when the Z68/Core i7-2600K combo is cheaper, still very capable, and equipped with Quick Sync support.
- Core i7-3930K And -3820 Get Reviewed
- Overclocking Sandy Bridge-E On A Budget
- Test Setup And Benchmarks
- Benchmark Results: PCMark 7
- Benchmark Results: 3DMark 11
- Benchmark Results: Sandra 2011
- Benchmark Results: Content Creation
- Benchmark Results: Productivity
- Benchmark Results: Media Encoding
- Benchmark Results: Crysis 2
- Benchmark Results: DiRT 3
- Benchmark Results: World Of Warcraft
- Core i7-3930K And -3820: Stock Versus Overclocked
- Core i7-3930K and -2600K: Making The Tough Choice
- Core i7-3930K: The Smart Sandy Bridge-E Choice
If by "noticeable" you mean "perceivable to mere mortals", then no.
If you can in fact notice the difference between 105 vs 110 FPS, then you are a god, and you deserve only the best.
Intel did an awesome job with the SBE line - despite the fact that we're missing some wanted/promised features (native support for USB and PCI-Express 3.0. I'm waiting out for the PCI 3.0 cards before I upgrade my graphics... curious if the Asus P9X79 Pro will hold it's promises.
Thanks Chris for reviewing this processor. I felt like I went out on a limb getting this processor over the Extreme, but the $600 was well worth it.
FX-8150 benchmark with no AA says "68.8" FPS. I think it's more like "48.8".
If by "noticeable" you mean "perceivable to mere mortals", then no.
If you can in fact notice the difference between 105 vs 110 FPS, then you are a god, and you deserve only the best.
Intel did an awesome job with the SBE line - despite the fact that we're missing some wanted/promised features (native support for USB and PCI-Express 3.0. I'm waiting out for the PCI 3.0 cards before I upgrade my graphics... curious if the Asus P9X79 Pro will hold it's promises.
Thanks Chris for reviewing this processor. I felt like I went out on a limb getting this processor over the Extreme, but the $600 was well worth it.
Glad you're enjoying. You do, actually get PCIe 3.0 support, but no USB 3.0, unfortunately.
Dacatak,
Yup, typo--fixing now!
it is a good thing
Indeed, fixed! At 3.6 V, we'd have dead Sandy.
Intel has made sure reviewers dont highlight on this factor, and instead asks reviewers to focus on the 6 core performance.
Intel didnt release the 4 core 3820(at launch) for this reason, it makes it easy to compare to normal sandy bridge and would show that even with a socket that is double the size, and quad channel memory X79 doesnt give you any better performance than Z68.
I always buy the high-end but X79 is a big letdown, Intel knows it and they're trying to control the reviews so it doesnt look as bad as it is
This shouldn't be necessary. Same architecture = same per-clock performance. If you need numbers, look at iTunes, WinZip, and Lame benchmark results. If you need yet additional proof, check out the original Sandy Bridge-E review, where I explicitly run the results you're saying don't get run.
Finally, as is mentioned in *this* story, the CPUs didn't come from Intel. -3930K came from Newegg and -3820, which isn't out yet, came from an unnamed other source.
Thanks,
Chris
it cant be the yield in Intel fab are so bad that all 2011 CPU produce by Intel have only 6 working cores at best.
This is the same as LGA 1366 v. LGA 1155 once the later was released. 1366 offered higher memory bandwidth and more Pci-e lanes, but even most enthusiasts wouldn't get the higher end platform due to price for performance.
Most settled for the i5-750(or lower since you could overclock anything then) just like most are settling for the 2500k now.