Xeons with an open multiplier

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foureight84

Active Member
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

Member
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

New Member
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)

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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

New Member
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

New Member
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

Member
Jun 23, 2016
71
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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

New Member
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

Member
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

New Member
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

Member
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. ;)
 

Retrorockit

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Mar 22, 2018
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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
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. ;)
The HP Z400 can be overclocked using Throttlestop software.
The thread starts here.
Throttlestop overclocking Desktop PCs

You do need to have one of the unlocked Xeons. Which one will work in your Z400 depends on which MB you have.
The older ones suppport W3570, W3580 Nehalem based Xeons these have 4 RAM slots. The newer ones with 6 RAM slots use the the W3680,W3690 Westmere based Xeons.
Itseems that TS is the best choice for software OC up to X58 systems, but XTU is better with later CPUs. It's just that's when it was developed.


Here's a newer Xeon overclock in a Dell T3610 workstation using Intel XTU from page 35 in that thread.

"Hey Guys!

I found a way to overclock Dell Precision T3610 + E5 1650 v2!

Installed XTU, TS 8.7. Set up all to unlimited in XTU or 4095 in TS.

Disable C states in Bios, enable speedstep, but in TS you have to disable it!

The only remaining is that you have to do a sleep in Windows, than turn on pc, woalla, your multiplier unlocked!

You need some heatsinks for the VRM to do 4400-4500 MHz(of course you need a decent chip), but with stock cooling the temps peaked at 78 C.

Dell computers (ex mine M4800) can step over TDP limitations, or weak PSU problems , aftermarket batteries when you do a sleep in Windows."

Dell Precision T3610 Performance Results - UserBenchmark
 
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8iosat

New Member
Nov 18, 2020
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I have owned the Xeon E5-1620, 1620 V2, 1650, 1650V2, 1660, 1680V2( and will buy a Xeon e5-1660V3 next week.


All of these E5-1600 Xeons are unlocked with an open Coremultiplikator. Only about the E5-1620V2 it was or is said, and i had to believe know it today, that its coremultiplier is locked at 43. Like it is locked in the Core I 7 3820 .

All E5-2600( v2) Xeons aren´t unlocked, don´t have an open core multiplikator and are vey difficult to overlock over the BCLk with the highest possible allcore Frequency.
Especially the E5-2690 is a chip which you shouldn´t try to overlock. Because your system can crash very hard!!

The easiest to overclock E5-1600 Xeon i know, is the E5-1680V2 which i use by the moment. You can adjust 4,4 GHZ allcore turbo by doing these settings in the bios, boot and have a stable oveclock( when you get the chip and are in the bios with this chip the first time!!). You can operate it with 8(16) x 4,7GHZ or even 4919 MHZ absolute stabile, when you have a good enough water cooler and adjust it opticaly.
But i recommend to set it to 8x4,4 GHZ or 4,6 maximum. Because the performance is nearly the same in games with 4,4 GHZ! Higher clocked ram than 1866 MHZ in my experience don´t scale very good.
The day i got it, i was in it´s CPUZ hall of fame with 5 places.

The E5-1650 is very easy to overclock,too. And with the the same frequency it is very near in it´s core power performance to an E5-1600V2 core.

The Xeon E5-1660( v0) is a bit special. It has an open core multiplikator, is unlocked. But a lot of people, overlocker blame this chip unoverlockable!

It isn´t so easy to overlock it over 4,7-4,8 GHZ. But this behaves because of the drilled out L3 cache to 15 MB compared to the 1650 with 12,5 MB together without the die shrink to 22 NM. Getting a chip made in the 32 nm manufacturing process, which needs so less power than this behaviour don´t overwhelmes, needs a little bit luck. Or the standby to buy 2 or 3 chips and sell the others when you have cherrypicked the best.

Because of that the E5-1660 becomes hot with frequencys over 4,6 GHz. It seems that it overvolts itself, not least over the pll voltage.
If you get a worser chip it can seem that frequencys over 4,7 or 4,8 GHZare impossible to reach.

But this bigger L3 cache makes this chip to my personal recommendation for a " bang for the bug" CPU. I bought one E5-1660 at ebay, as used of course, i´ve bought every E5-1600 Xeon as used, and got in its CPUZ hall of fame with ~4910 MHZ in 2 positions 13 and 15. But today its hof starts a little bit higher than my overlock was:(.

But with the E5-1680 v2, which i´ve bought as used on ebay, i still hold 8 or 9 of 15 positions in this hall of fame. Don´t want to say that i am such a good and important overlocker, but I'm apparently not the worst either, maybe??

The E5-1660 is very near in it´s performance, to the overpriced, the most overpriced E5-1600V2 CPU, the E5-1660 V2. Its performance is very good for a 60€ chip.
It feels much smoother than the 1650 which has almost the same performace with the same clock on the data sheet, .

Another Xeons, E5-1600 Xeons with open coremultiplier are the identical CPU´s E5-1660V3 and 1680 V3. I couldn´t believe it on my own, that the E5-1660V3 is an E5-1680V3 with 8 cores 16 threads the identical data sheet with just a ~300MHZ lower preset frequency. Because of that i made up my mind to buy a x99 Board( EVGA X99 classified or Asus x99 WS sage) and an E5-1660V3. The E5-1680V3 is in default settings only a bit slower in the multicore score than my maxed out E5-1680 v2!!( If my mother lends me 200 i will get an EVGa x299 FTW K and a Core i9 7900X)

Another Xeon with an open core multiplier is the very expensive Xeon W3175X which Asus dominator mobo is unrealisticaly cool!! But unrealistic expensive, too. the mobo and the chip aswell!
 
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Retrorockit

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Mar 22, 2018
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I'd like to report a successful overclock of a Dell T5810 workstation using an unlocked Xeon E5-1650z3 to 4.5GHz.
The Xeon is known to be unlocked, but we weren't sure if the workstation chipset would allow overclocking in these systems.
Intel XTU, and Throttlestop software can do this on the locked BIOS system. Throttlestop is preferred by this user. His posts start at #1018 on this page.
WARNING Dell went to a proprietary plug and play PSU format on their workstations newer than T3500. Do your research on this if you want run a bigger PSU in one of these.
 
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