Z620 CPU Update

[Xgamerz]

Hi all,
first thanks to all contributors like (Brian1965, Bambi, SDH, DGroves and many others ...) for all informations provided in forum

I own a Z620 v2 dual E5-2670, 64GB ram dual gpu (AMD & NVidia). i suffered from many issues for years, now with some tips from Brian1965, it become stable until the moment, and temperature is fine with +1 in power thermal.

- the famous QPI link error for long time (i did a shower to motherboard :d). 
- fan's RPM was static whatever the cpu load (solved by reseting bios)
- heat due to some old bios config & bad thermal paste (solved by reseting bios)
- cpu frequency never touched the max turbo (now it become consistant (solved by reseting bios)
- last few days ago got some shutdowns maybe due to this error :  (re-mounted riser and it disappear)

A corrected hardware error has occurred.

Reported by component: Processor Core
Error Source: Corrected Machine Check
Error Type: Bus/Interconnect Error
Processor APIC ID: 32

The details view of this entry contains further information.

now im using 2 differents thermal pastes, main cpu has IC Diamond, and riser MX-4, 
- temperature of the main one (idle 38-45) (normal load 55-65) (max load 75-79)
- temperature of riser is lower than main ! (idle 30-40) (normal load 50-60) (max load 75-79)
the only thing for MX-4 is hitting max load temperature before IC Diamon during Cinebench

the picture taken just before ending of cinebench

im thinking to update CPU's, there 3 options E5-(2650, 2680, 2667) v2
- to keep thing safe and stable for me looks 2650 is the choice, has same cores count, base clock, turbo+1 and less TDP
- 2680 more cores, base clock+2 turbo+3 same TDP as 2670v1, (expecting same temperature).
- 2667 risky choice everthing is higher.

is there someone experienced any of these on dual mode with stock heatsink ?  and what is the temperature expected ?
also all riser's support v2 ? or only some specific reference ?

[Brian1965 · Accepted solution]

Please be aware that there is no correlation between CPU temperature and CPU power consumption (TDP). The amount of heat generated under full load by the CPU is dictated by the CPU design/layout. e.g.

E5-2650 v2 - 95W - Tcase 75°C - 8 core - 2.6/3.4GHz

E5-2680 v2 - 115W - Tcase 82°C - 10 core - 2.8/3.6GHz

E5-2667 v2 - 130W - Tcase 74°C - 8 core - 3.3/4.0GHz

Actually the 2667 v2 CPU will (marginally) run the coolest of the above CPU's and is the CPU I would recommend. I have used the 2667 v2 in my Z620 previously and this is a very fast CPU and great multi-core performance.

[SDH]

Xgamerz,

You've clearly done your homework so I'm betting you know of my discovery that the Z440/Z640 single-processor build heatsink fits perfectly atop the corresponding sockets in the Z420/Z620 single-processor workstations.  My testing and application of this has solely been related to the single-processor builds up to this point.  You may want to do this project since you watch the temps carefully, and this idea might allow you to run your upgraded dual-processor Z620 more quietly (especially if you do some overclocking).  The two Z640 dual-processor heatsinks I refer to below have 4 instead of 3 heat tubes, and may also have more cooling fin surface areas.  I measured the single-processor Z440/Z640 heatsink I'm using and it has just beneath 2x the surface area when compared to the stock Z420/Z620 mainboard heatsink.  You can search eBay for 749554-001 to see that.  It is bigger than the stock ZX20 one (647287-001) and the two ZX40 ones I reference below.  It can be bigger for a single-processor build because there was more room to play with by the HP engineers.  It fits perfectly under the Z620 active memory cooling "saddle" also.  HP needed to add in more cooling for the hottest running v3/v4 processors used in the ZX40 workstations, and we ZX20 tinkerers benefit from these better heatsinks now, for low cost.

There are two different processor heatsinks for your dual-processor Z620 build, one below on the motherboard and one above.  There is the plug-in "second processor riser" (that some refer to as the mini-motherboard) for readers who don't know that.  The form factors between the Z620 and the Z640 are nearly identical.  HP had to engineer in higher cooling capacity for all the ZX40 heatsinks because their newer processors can generate more heat.  Thus, you can almost certainly use both of the dual-processor build heatsinks from a Z640 on a Z620 to get better cooling.

The first 4 pins on the HP motherboard heatsink's fan plugs have been in the PWM standard order (ground, 12VDC, rotor sense, PWM control from motherboard back to rotor).  Then, the fifth pin also gets a ground wire swung over from pin 1, in the Z620.  For the Z640 HP added another ground pin swung over from pin 5 to 6... those three grounds are all the same, in continuity.  So, you just hang the 6th plug hole 1/8" out in space when plugging a 6-pin plug into the Z620/Z420 motherboard CPU fan header.

I checked the pictures on eBay to see if they use a 6-pin plug the same way on the riser for its processor heatsink fan... they use a HP-type 4-pin white PWM fan plug instead, shown below.  That Z640 "second CPU" heatsink/fan is rotated roughly 45 degrees on its CPU contact plate, shows 3 instead of 4 heat tubes, has part number 749597-001, and here is about $18.00 USD with shipping included as the lowest current cost.

The dual processor build mainboard's processor heatsink/fan also has 4 instead of 3 heat tubes, is not rotated, and may have higher cooling fin surface area.  Its visible part number is 749596-001, and has a bit higher eBay price.  You can view a number of these heatsinks easily via an eBay search for their part numbers, and here are two pics:

Edit:  HP's PWM control strategy has been to use native quite high speed PWM fans and then apply strong PWM braking to them.  This way by pulling down the level of braking the fans can really ramp up their speed as needed in special high-heat circumstances.  Thus, if you put a nice quiet slow non-HP PWM-controlled fan in place of the stock one you get the same strong PWM braking applied to it and now your Noctua is going way too slow.  I think HP also gets better bearings this way too, and that helps their critical-function fans last so long.  I generally stick with the HP fans at all positions but do admit to dinking with this some using other same-size HP PWM fans that I've found to run slower at lowest BIOS fans speed settings.  Our applications never really stress the processor(s) like Brian, Bambi and DGroves do.

[savvy2]

"CPU is dictated by the CPU design/layout. e.g." so true.

that is covered in the CPU data sheet

the CPU uses aggressive and dynamic thermal throttling, (and if too hot shuts itself off !) saving the bacon, yes.

and varies by CPU model number.

it is not predictable at all (it can but not you)!

some CPU overheat at 90c others  130c, again RTM.

most start throttling inside at 80 to 90c, but RTM read the data sheet. (varies by package type too, and mobile too)

best is not go near 90c for most CPU,  also high heat lower life of the silicon, (google that) in fact mil testing does just that.

use the correct heat sink and fan, for CPU choice.

use Shin Estu heat sink grease there is no better, do not read hype sites fibs on , silver that is not even in the tube.

most silver hype is actually aluminum powered or AL oxide. not silver,   we have fed and out side labs to prove that.

keep inside case cool,  use  extra case fans if you  see inside case temps rise, add them,

[Xgamerz]

Thanks, i will check availability of these in my region ! it not easy task to order from where i'm.
the idea is to see which Zx40 heatsink is fit to Z620 mainboard ? or both motherboard & miniboard ?
but to be honest not going to make that step until i change cpu, to see if needed or not.

[Xgamerz]

Thanks, already did some of these tips few months ago and it was good idea to add some intake and exhaust fans most of time during summer, but now they are removed.

getting some high quality parts & termal paste here is not easy task, so don't think i can find Shin Etsu here !