Xeons with an open multiplier

bsmith

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Jul 13, 2018
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I have unintentionally got myself into a state where CPU-Z misreported during BCLK overclocking. Of course I did not submit the results... This seemed to me to be a bug in the application, but I no longer trust it completely.
 
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wellen1981

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Nov 21, 2018
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Hi all, just wanted to post with some thoughts, findings, and the odd question...

My thoughts
I think a lot of the confusion comes from the fact that even if users grab a Xeon with an unlocked multi, it can sometimes be simply their method of testing that leads them to an incorrect conclusion - an example of this is Intel XTU software - certain versions of XTU do not allow certain unlocked Xeons to show as overclockable.
Regarding people finding screenshots eg CPU-Z of certain Xeons with what appears to be higher than stock multis, I would say to avoid this thread ending up with lots of incorrect assumptions it would be best if users who have personal experience with each Xeon multi overclocked are used for adding Xeons to this threads first post.
Eg if someone owns the Xeon and has actually overclocked it past turbo using the multi increase - then it is safe for the chip to be in this threads list.

My findings
I have experience with LGA1366 Xeon W3680 and HP Z400 Workstation (Version 2). I can use Intel XTU to increase the multi but there are a few versions of XTU that dont work and give the impression that the CPU is locked - therefore people need to be cautious when testing and make sure they try various different versions of Intel XTU to be sure of their own findings.

My questions
I am under the impression that LGA1366 Intel Xeon X5680 and X5690 are locked multiplier but does anyone here have evidence that proves otherwise? Eg has anyone managed to use Intel XTU to increase the multiplier past turbo?

Thanks all for reading and I was posting about Z400 and W3680 on overclockers in case you wondered.

Cheers
 
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Retrorockit

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Mar 22, 2018
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We've been using Throttlestop to overclock these, so the XTU issue isn't the problem, and all the 2 QPI 5500, and 5600 Xeons are coming up locked. W or X or even ES series.
In LGA 1366 all the ones coming up unlocked have an unlocked equvalent like the i7-875X, i7-980X,i7-990X etc.
The only dual CPU LGA1366 overclocks I've seen are on the unlocked EVGA Classified SR2 motherboard.
The other thing we're finding is that the dual CPU motherboards don't support the unlocked ( or any) single CPU chips even in single CPU configuration. They're 5500/5600 series Xeons only.
 

Milli

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Apr 5, 2019
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So if I understand correctly, the W3670 isn't unlocked even though it's the same core?
 

foureight84

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Jun 26, 2018
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Apparently there's OEM haswell 1681 V3, 1686 v3, and 1691 V3. I'm interested to find out if these are unlocked but can't find them anywhere.
 

BlackArchon

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Jun 23, 2016
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I assume there are quite a few people who want to get one of these CPUs, however I haven't seen them in the real world. I'm not sure if they really exist.
 

derviking

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Aug 19, 2019
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Multiplier-unlocked Xeons according to overclocking results from HWBOT:
Bloomfield:
W3565 (source)
W3570 (source)
W3580 (uncertain)
Gulftown:
W3680
W3690
Gainestown:
W5580 (most probably not unlocked, despite of one CPU-Z validation; please see also https://forums.servethehome.com/ind...h-an-open-multiplier.15983/page-5#post-209642)
W5590 (most probably not unlocked)
Sandy Bridge-EP:
E5-1620 (source - max CPU multiplier is 43, just like the i7-3820)
E5-1650
E5-1660
Ivy Bridge-EP:
E5-1620 v2 (source)
E5-1650 v2
E5-1660 v2
E5-1680 v2
Haswell-EP:
E5-1650 v3
E5-1660 v3
E5-1680 v3
Broadwell-EP:
None
Skylake-W:
W-3175X

Additional confirmed observations:
- all Xeon E5 v3 with C2 stepping can be clocked all cores to max turbo multiplier (called Xeon turbo core exploit)

----

Since there don't seem to be a definite source about which Xeons are overclockable by changing their frequency multiplier, I want to create one.
While "common knowledge" of most people seems to be that Xeons don't have an open multiplier, a few guys know it better. For example, my Xeon E5-1680 v2 can be overclocked solely by changing the CPU multiplier.

When googling terms like "xeon overclockable", you will occasionally find statements like "the E5-16xx series Xeons have an open multiplier when there is an equivalent i7" or "all E5-16xx series Xeons are overclockable from the model number of 1650 and upwards" or "this only applies to v1, v2 and v3 Xeons". While all of these statements seems to be correct to a certain point, I got the feeling that noone really knows exactly.
The fact that there are hardly any reviews of these Xeons out there emphasizes the uncertainty.

So please share your knowledge, and if you got sources or screenshots of an multiplier-overclocked Xeon, please post them in this thread. I will edit this first entry and collect the facts in the hope to shed light into Xeon overclocking once and for all. :)

I will start with my semi-knowledge:
- There are only overclockable Xeons from the E5-1600 series range of processors, the E5-2600 are all locked (quite sure)
- Beginning with the v4 Xeons, they are all locked (someone at the HardOCP forums stated this)
 

derviking

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Aug 19, 2019
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the w3565 is locked I know as I have it and have found it locked using evga board also wxeons no ecc memory
 

Retrorockit

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Mar 22, 2018
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I have a user at the Throttlestop overclocking thread who wants to overclock his E5-1660V2 Xeon.
The CPUZ 1660v2 chart seems to have unlocked E5=1620v2 results in it for some reason.
We're finding lots of Dell T3610 workstation E5-1650v2 overclocks at userbenchmark,com but the 1660 remains a mystery.
So is the E5-1660v2 confirmed multiplier unlocked.
and, is there any evidence that Intel is using the Spectre/Meltdown microcode patch to lock these xeons back up?
The ones at CPUZ are flagged as needing this.
 

BlackArchon

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Jun 23, 2016
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...
and, is there any evidence that Intel is using the Spectre/Meltdown microcode patch to lock these xeons back up?
...
I don't think so, at least I haven't found anyone mentioning that their overclockable Xeons suddenly stopped being overclockable after installing the latest Windows patches or modding their BIOSes to integrate the new microcodes.
 

Biomecanoid

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Jan 12, 2020
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So i just bought the x5690 for my HP Z400 and according to this thread its not overclockable because it has a locked multiplier right ?
I guess i made a mistake and should have gotten the w5690 ? :/
 

BlackArchon

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Jun 23, 2016
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The Xeon X5690 doesn't seem to have an unlocked multiplier, but you can overclock locked Nehalem-based CPUs by changing their reference base clock.
 

Biomecanoid

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Jan 12, 2020
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The Xeon X5690 doesn't seem to have an unlocked multiplier, but you can overclock locked Nehalem-based CPUs by changing their reference base clock.
How can i do that on a HP z400 with windows10 the bios does not provide any settings regarding overclock. Can i do this via software on windows ? XTU and ThrottleStop dont work i tried them
 

BlackArchon

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Jun 23, 2016
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I don't know which software tools are to be used, since I've never used a Nehalem CPU. However, I think you should better ask in a true overclocking forum. ;)