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[Mod Blog] Dell PowerEdge 6850 server to desktop conversion

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I acquired a Dell PowerEdge 6850 and a PowerVault 220S from my boss (so swell)! Since I don't have a desktop I figured... "how hard could it be" to make this server into a desktop! Answer: it's really heavy --- I mean difficult


PowerEdge 6850:

Four Xeon 7140M = Hyperthreaded Dual-Core 3.4 GHz

16x 4GB DDR2 @ 200 MHz = 64GB total

5x 450GB 15k RPM SCSI = 1.63 TiB total (Tebibyte/formatted)

pair of 110V -> 220V 1500W transformers

PowerVault 220S:

14x 73GB 15k RPM SCSI

Notes about each

PowerEdge 6850:

  • came with Windows Server 2008 R2 | ugly for desktop OS | only supported 32GB RAM
  • not terribly loud | with my audio setup it would drown it out | sits opposite side of desk so noise is tolerable
  • Runs off of 220V | thus the 110V -> 220V step-up transformers
  • HEAVY | I'm not going to your LAN party, sorry bub

PowerVault 220S:

  • SCSI connection | older SCSI hardware doesn't work with Windows Server 2012 R2 | so is sitting off to side unused
  • For today's times, this is a bit excessive for the 1TB of storage it gives. I'll stick to external HDDs
  • heavy | not as bad as the 6850, but still a chore to lug around


Step 1 (OS):

So I started by changing the OS. Pretty straightforward... not really.

Since I want it to be a desktop and not a server, I initially tried Windows 8.1 (I like Win8.1). Turns out Win8.1 doesn't support more than 2 physical CPUs, which in this case isn't nice. I attempted to force more than 2 physical CPUs to no avail. You can see my efforts here:


Since I'm a student, I was able to join the Microsoft Dreamspark and get Windows Server 2012 R2 Datacenter. Very nice!

I then followed the information provided here to make WinSrv behave more like it's desktop OS counterpart:


This got me a bulk of the way there.... or so I hoped.



No really, please don't hate me..



Why do you hate me...



The CPUs are right there, all of them!



Windows Server 2012 R2 Datacenter loves me :D



That seq. read speed is faster than my Intel 520 Series 60GB SSD @@.... (480MB/s)


Step 2 (GPU):

Here I was hoping I could just plug in a GPU and get it working after a driver install... heh. that was a funny joke...

I cut away the backside of the PCIe 8x slot (wired 8x) to make it an edgeless connector. This was successful. But:

  • Server PCI widths are not the same, double wide cards don't fit
  • Server motherboard doesn't put out adequate power, assuming 25W instead of the normal 75W
  • Reflectional thought: May have been a PRSNT1# and PRSNT2# issue which I discovered about later instead of the above

Soooo, I bought a powered 8x to 16x extender cable. I knew coming into this I'd have an external PSU (ePSU). I soldered on a GND to the cable (only had +12V since it assumed there would just be one PSU and the ground going through the mobo and whatnot). And plugged this all together..... nothing.

Got some reference material here: [Guide] Homebrew powered risers.

So then I started looking around for why. I found this:


(With all the BTC and LTC mining, lots of info on risers)

This turned out to be the ticket! I bridged A1 to B48 and BOOM, card turned on. Big thanks to @chmod1337 for his help with this section.

I was doing this testing with an old 8800GTS (this is important for later).

I finalized the extender by soldering the bridge nice and neat then.... (next step)



No spinning!



PRSNT1# connected to 8x PRSNT2#



Dat side view




Should've come like this!





Step 3 (case / making it look remotely decent):

This will be just a series of pictures mainly. I used the same case as I did with my eGPU. Actually, nothing changed but the interface cable and a new hole cut. Quite nice.



Hole cut in server cover to allow extender to come through



eGPU box to be modified some more @@



It looks like it'll work!


Hooking it up:


Through the server lid...







Step 4 (Nvidia woes):

8800GTs worked great! It's actually what I'm using while I type this post up.

GTX 660 Ti:

  • Works during POST and other pre-boot environment areas, also in DOS
  • Blackscreen and makes the system beep when it loads any thing else (and just before entering BIOS setup and DOS)
  • Doesn't work for anything else
  • @svl7 helped me with some info (paraphrase): nvidia loads a leagacy vBIOS for pre-boot environment and such, thus it worked here. But loads a different vBIOS for OS and such. This might be were the issue arises. (svl7, feel free to edit this to make it more accurate)

I plan to get my hands on a friend's AMD card (R9 280X). If that works to getting me to the OS then:

  • I jump around in an overly excited manner.
  • Look in wallet and find nothing useful, and then proceed to halt jumping around in an overly excited manner. :86:
  • Realize this is a pure Nvidia problem and that their modern cards are far too finicky and can't use them for this Server GPU setup. Resulting in AMD being the choice for this Server GPU project. Newer servers may not have this issue.

Thanks to @svl7 for help in this section!

Quick Edit: The R9 280X works, albeit slowly. See the links at the bottom of post for results of that.



All hooked up...


Off the analogue connection.


Off the 8800GTS (I should've taken a screenshot, but my phone/camera was handy)


GTX 660 Ti booting to DOS (in hopes of a different vBIOS would resolve problem):



Glorious artifacts ;-;


Step 5 (testing):

At the moment, I can't do anything too impressive. You can satisfy your appetite with this hopefully, more soon if I can get this working fully.

NVIDIA GeForce 8800 GTS 320MB/640MB video card benchmark result - Intel® Xeon™ CPU 3.40GHz,Dell Computer Corporation 0RD318

Doesn't appear to use / doesn't actually use all CPUs:



Step 6 (endnotes):

Carrying this up stairs wasn't fun. I'm not moving it more than dragging around a few feet.

If this does end up working more than it does now, it'll be a glorious moment. Certainly look forward to it.

I'll have more in this section later.


R9 280X::

Link storage zone for writeup:




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  • 4 weeks later...

Sounds nice (I'd say looks nice too but I can't see the pics (not enough posts)).

I have a slight fetish for workstation hardware... my two main rigs both are based on such. Both are older motherboards though (both run DDR); one is based off a supermicro X5DAL-TG2 (twin Xeon gallatin+ HIS ATI HD4670 1gb AGP), the better one is based of a Tyan S2895 Thunder K8WE (twin Opteron x2 Italy + 2x SLI 8600GTs).

Both built up reasonably well (and kick ass for productivity) but as you found out, they can sometimes be a PAIN to run right. The worst I've run into was the nicer system's first attempt, a Tyan S2885 K8W. The problem was the damn AMD 8131 AGP to Hyper transport bridge... No linux support. No XP x64 support. No Vista or later support. Basically, no x64 support AT ALL. Try to install GPU drivers, you get a BSOD next bootup. Granted, it was a 1st generation opteron board... but the whole F**king point of opteron WAS x64. Way to F**king ruin a workstation platform, AMD! Due to all the issues, I ended up with two of these no less (both recapped even by yours truly)... both collecting dust (but if I ever score some more EATX cases, I may headless them with some RAGE server GPU's I have sitting).

Luckily, the replacement had a kickass Nforce Professional 2000 setup, which runs 7 (and probably linux) beautifully. Twin X16 PCI E's with SLI too... it may be old, but I love the setup... all I need are nicer GPU's and a beefier PSU (as my 600W seasonic isn't enough for better GPU's on top of everything else) and that will rock.

Sorry for the long post and long live workstations! :D

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  • 1 year later...

Too cool. Pity I didn't find this some time ago as I'm doing the same.

I managed to get my PE 6850 to install Windows 8.1. This was inspired by the inability of my PE 2850 to install 8.1. The PE 2850 can install Windows 7 and 8, but the CPU spec changed for 8.1 and 10. That's for another day. The important take away is the dual core CPUs I have (3.4ghz?) do have the necessary microcode and can run Windows 10 (I've managed 8.1 before I mothballed the unit). I accept that I can only run 2xCPU, but I'm not happy about it. Unfortunately I have 3 working CPUs and would have to buy a fourth to test the suggested registry change.

The other significant problem was finding SCSI drivers. I managed that through research and trial-and-error, but don't have any links handy. Have I said what a great job angerthosenear did with his documentation and links?

On my PE 2850 I removed the back of the PCIe x8 slot with a red hot screwdriver. Simple process really. Don't be afraid. With that gone I was able to manage an AMD HD5670, which required less than 75w. Through some soldering to the power supply I was able to upgrade to an HD7950. As noted the PE6850 only bothers to pump 25w through the PCIe, which got me stuck. Not wanting to run a large enough 110v-220v inverter, I ran a 220v outlet from the circuit breaker box.

At some point along the way I had to upgrade the PE6850 motherboard to a newer version, probably to support dual-core. I also had to solve the double-wide card spacing problem, but I think that was done by bending something on the motherboard. Can't think of what it might have been.

Next step was to run +12vdc and ground wires through the chassis to the power supply. On the PE6850 this is not nearly as easy as it sounds. That's where I got stuck and mothballed the project. This article might inspire me to get it moving again as I'd really like to get this off my work desk.

Let's say I do. Do I spring for a second (third?) HD 7950 and attempt Cross-Fire? I've got oodles of watts and cooling to play with, it would be super cool to do it. The problem is I can't conceive of Dell supporting Cross-Fire unless they did so by accident. Who thinks it's possible?

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