Intel Xeon X5550: Uncore clock tied to core clock?

[laamanaator]

I bought a Xeon x5550(cost me 15€, real cheap), and as i tried to OC it, i noticed, that the Uncore clock(NB in CPU-Z) seems to be tied to the core clock it self, and thus, i wasn't able to get past 4ghz. I tried to change the uncore multiplier, so that it would not limit the oc, but it had no effect, still the same as core clock. I'm currently running it at a stable 4ghz@1,28V overclock, but because the temps are so low, it would be nice to get some more OC. Does anyone have an idea how to "untie" the uncore clock, or is this some sort of a bug, that should not happen?
My specs, if you need them:
CPU cooler: Thermalright HR-02 macho rev.A
Motherboard: Gigabyte GA-X58A UD3R (FH bios, latest)
Memory: Kingston valueram 2*4GB 1333@1600mhz
PSU: XFX 550wcore edition
Graphics: R7870@1200/1400

 

[ClockHound]

On my Sabertooth you can change the uncore clock. No idea on a UD3R tho.

Have you checked the big Xeon thread?
http://forums.anandtech.com/showthread.php?t=2335636&page=51

It's not even a hundred pages, so could sift thru that in a few minutes. ;-)

Or you could post your question there. You could also PM, Burpo, Official Anand Hex-Core Xeon Advocate.

 

[Burpo]

Uncore is tied to your ram speed. If your ram speed is 1600mhz then set spd system memory multiplier to 10x, set uncore freq to 20x, or use 21x191 (system clk) and then use 8x mem multiplier (191x8) which will let you run ram speed at 1528mhz and set uncore freq to 16x. I also didn't have much luck with X5550 getting past 4Ghz with Gigabyte boards. The Asus SaberTooth is no problem running 4.2 or even 4.4 with enough volts.

Also i see you're running dual channel memory (only 2 sticks). Performs better with 3..

 

[laamanaator]

I did as you told, but when i booted to windows with uncore 16*191, it had changed to 20*191, but in bios, showed that it was still 16x. And the 21x multiplier for processor doesn't work, it changes back to 20. I think that the 21, 22 and 23x multipliers are the intel turbo boost multipliers, and function only when it's enabled. So again, the uncore changed to the same frequency as the processor.

How big is the performance boost with triple channel?

 

[myocardia]

How big is the performance boost with triple channel?

It's close to 0%, when running software that is not RAM-intensive, and closer to 30% or slightly higher, when using software that is RAM-intensive. You're using 2 of 3 channels, giving you 2/3, or 66.6%, of the available bandwidth.

 

[Burpo]

You don't have turbo enabled? C states? Why? That board overclocks fine with all features on.

See below post for difference 1 stick of ram makes..
http://forums.anandtech.com/showpost.php?p=37273554&postcount=2206


Settings on your Gigabyte board should look similar to this, just up the Bclk & volts and match memory settings to 1600 for higher overclock. That board locks in 22X with an X5550, no problem if everything's enabled.. That's when temps go up.. This was just a slight initial overclock of my $15 X5550, with the intel cooler. I have since switched to a $15 E5640 and it is currently running 4400mhz. I'm waiting on a pair of X5650 Hexcores to get here tho. I paid $95 for the pair
Anyway here is initial settings for X5550. Just up the bclk & volts & keep memory in spec.

http://forums.anandtech.com/showpost.php?p=37452436&postcount=2361

 

[laamanaator]

I disable them because when i'm searching for the highest frequency within temps and volts, i want to eliminate any possible instability caused by them. But apparently in this case, the intel turbo boost worked as workaround to get past 4ghz, so a big thank you for that idea! I achieved 4,2ghz with reasonable volts(1,344 after vdroop, might go even lower, but i haven't tried yet), but 4,4ghz is not achievable with reasonable volts. It'd require at least 1,5V to get that stable.

But do you have any idea why the uncore seems to be locked at 20x? Changing the ratio from bios doesn't have any effect.

And lastly, do X5600 series xeons work with this motherboard? They aren't in the cpu support list in gigabytes sites, but the other 32nm westmere consumer processors are, and aren't xeons using exactly the same die as the consumer processors?

 

[Burpo]

Yes, the X5650 Xeon's work with your board. They may be from the same die, but instruction set is different, and at 95 watts instead of 130, you have a little more head room for overclocking before heat becomes an issue.

http://www.hw-benchmarks.com/compare/Intel Core i7-970 Gulftown/Intel Xeon X5675 Westmere-EP/

i7 970: TCASE 67.9°C
http://ark.intel.com/products/47933...ocessor-12M-Cache-3_20-GHz-4_80-GTs-Intel-QPI

X5650-X5675: TCASE 81.3°C
http://ark.intel.com/products/52577/Intel-Xeon-Processor-X5675-12M-Cache-3_06-GHz-6_40-GTs-Intel-QPI

Uncore can't be higher than default multiplier of CPU..

 

[laamanaator]

Thanks, thats good to know! That means i can use the x58 platform for years to come.

 

[Burpo]

Yes you sure can & there's nothing quite as satisfying as overclocking an old $50 CPU, and kicking arse on a 4790K & running next to a stock 5820K