TK025 Dual Graphics Riser for T7400 in Dell Precision 690 ?

The reason the 690 needs the riser is because the 690 MOBO does not have the integrated Nvidia SLI chip necessary to run 2 cards in an SLI configuration.  I assume this was also omitted in the T7400, thus requiring the riser to run SLI.  As for being compatible, I don't know for sure, but they might be.  The T7400 supports PCIe 16x Gen 2 video cards, and I believe the precision 690 is not.  When PCIe 2.0 was introduced it retained backwards compatibility with most earlier PCIe 16x motherboards, but this is a dell proprietary design, so they may have made the decision not to maintain backwards compatibility.  That, or, as with all of their business class machines that undergo are highly engineered and undergo rigorous testing prior to release, they may simply have not bothered to spend the money on testing the new board on 'last year's model'.  The t7400 listed the riser as a 'time of purchase only' option, so they may not have people like us do what we're doing.

I say we, because I'm in the process of taking my 690 from a single Quadro FX 4500 into a dual card SLI configuration.  In addition to the riser, you also need some additional parts because the 'stock' pan will not support the riser install.  You're going to need a Dell Precision 690 Riser Card Assembly Kit (TH757 D8794), which includes a different card fan (the slots that support full length cards are different), a different rear pan (to handle the offset caused by the riser), and card support bracket (also to support the offset).  You also need the SLI Bridge (MJ247), and the correct cabling to power it all.  

That's the roadblock I'm at right now, so maybe we can help each other.  Their first response was that it was a standard 4 pin Molex cable, which is wrong.  From what I can tell, the power slot on the riser is keyed to an 8 pin EPS connector, and not a 6+2 or 8 pin PCIe connector.  I spent a lot of time chatting with Dell's tech support which was a complete waste of time.  My case does not have the power cable for the PCI riser, and no one at Dell was able to tell me the correct pinout or even the part number for the riser power cable.  By the way, if you don't have it, Dell is out of stock, so you're in the same boat I am.  

SOO, if you happen to have the 8 pin connector in your case, I would REALLY appreciate it if you could take closeup pictures of both sides at each of the ends of the graphics riser card power cable.   Since Dell uses nonstandard colors in its wiring, it's not very easy to figure out (especially for someone as slow as I am.  From what I can see from dozens of terrible pictures I've looked at online, Pins 1 & possibly 4 are 12v (blue w/ white stripe), 2,3,5,&6 appear to be grounds, and pins 4 & 8 are either red (+6v) or orange (+3.3v).  Don't just buy a Molex to EPS adapter, it'll run +12v to pins 1-4 and ground 5-8, which will cook your video cards.  

I really hope this helps (and also gets me the pics and / or a pinout from someone who knows what it should be, cauz i'm going nuts trying to find it)!  Cheers!!!

Robinet,

Thanks for the reply!  I am running the 750w PSU, but when I asked Dell support whether I needed to upgrade to the 1kw PSU, they said no, the riser & dual VCs in SLI would work with the 750w psu, and their install kit (out of stock) had the correct cable in it.  Whether I believe it or not is another story, but plan to cut the draw on the +12v rail by installing lower amperage (and lower noise) fans.  Between the 4 installed, I'm fairly sure I can cut the 70w-ish needed for the 2 FX4500s.  The draw of the riser is another issue, but it's worth a shot for now anyway.  The issue I'm running into is whether the cable running the riser is actually PCIe or if it's something Dell setup in a nonstandard pin configuration. From the aftermarket PSUs I found last night, it appears to be PCIe 8 pin, with an 8 pin EPS +12 connector, but I still want to confirm so I don't roast anything.  The below link shows how the PCIe 8x is keyed and pinned, versus the EPS, and that's really what has me concerned.   

www.playtool.com/.../connectors.html

Back to the RAID idea...Interesting application for the riser, hadn't even thought of running RAID cards on the riser...I really wonder if it'll work. You got me thinking, and my third thought was that one potential downside of using the riser for your array is that the riser splits the 64 bit channel offered by PCIe16x into 2x32 bit channels, one for each slot on the riser.  How your setup is configured and what RAID card(s) are you planning on using on the riser?  Are they hardware or software?  Reason I ask is b/c my PCI-x software RAID controller just arrived in the mail (Syba PCRDSATACO11)...for this project's budget, it'll have to do for now.  

My 'plan' is to run the OS off the integrated controller (3x15k Cheetah 73gb SAS drives in RAID 0 for now) with 10 tb of storage off the Syba (4x2tb in RAID 5).  I know I lose parity on the OS drive, but I'll use another 250gb drive as a dedicated automatic backup for the OS array (weekly should be okay for me).  The Syba will fit in one of the 2 remaining PCI-x slots, it'll handle 64 bit throughput (SATA II only) and keeps the one remaining PCIe 8x slot open, which gives me the option to add parity to the OS via the PERC 5i (XT257) in the future.  With a 3x3.5" drive in 2x5.25" bay hot swap SAS enclosure (bay 3&4 for the OS drives), I can fit both arrays, a BDRW (Bay 1), and the backup drive (Bay 2) internal, and leave the sawzall in the basement :). The hot swap enclosure is still TBD, but with a possible PERC 5i in the future, it seems like something that could be worth it.  This is really a 'see if I can' project, and is still a work in progress, so what do you think?    Thanks again!!!

Hi again ;)

This part will be about RAID cards ;)

I have PERC 5/i, 6/i, 5/e, 2x 6/e and I think 2x 5/iR ;)

Of course I can't install all of them together ;) I'll keep 6/i or 6/e (512MB TBBU) - the rest would be available on eBay ;)

If you can change your future plans - DON'T go for PERC 5/i !! Buy PERC 6/i - less ram and not upgradeable, "only" 256MB on board - but it's MUCH faster than PERC 5/i with 512MB cache.

Or you can try to find PERC 6/e with 512MB cache + integrated TBBU. Remember that PERC 6/e will need special cables if you want to connect "internal" drives.

I'm not sure about new models - H700, H800 and other - but they are more expensive ... And there could be problem with non-DELL-rebranded drives.

I'm not "capacity" fan ;) I'm more "speed" fan ;) I know ;) I should probably go for SSD drives - but they are still too expensive per 1GB ;)

I also bought few DELL and HP sas backplanes - just for testing and for fun ;) and because I won them very cheap on eBay ;)

There is a great thread here:

http://www.overclock.net/raid-controllers-software/359025-perc-5-i-raid-card-tips.html

566 pages and 5659 posts - it's very good knowledge base ;)

I know that PIC-E riser will work as splitter - but PERC 5 and 6 requires only x8 wired slot for full preformance - riser working as splitter shouldn't be a problem ;)

[...] with 10 tb of storage off the Syba (4x2tb in RAID 5).

Are you sure ? ;) For me it would be 3x 2TB + 2TB for parity = 6TB for data.

cheers

Hi,

I think this might be your lucky day :emotion-2:

It seems that 1kW PSU HAVE correct connector - but I can't guarantee this !!

It's called P11:

And wires position:

There are also 2x PCI-E power connectors for graphics cards - P5 and P10:

Cheers :emotion-2:

THANK YOU FOR THE PICS!  

WRT the Syba, I am no math magician, but doesn't 4x2tb - 2tb for parity = 10! :)  I must've been more tired than I thought last night!  Actually, the 10tb array was my original concept (8 + 2 for parity) until I realized dell split the 5.25 bays into 2+2, preventing me from going with a 5x3.5 in 3x5.25 hot swap enclosure (without using the sawzall).  I knew the Syba wasn't going to get me the 5th drive, but I figured by then, I could pickup another 6 or 8 drive controller and drop in another 2tb drive then.

Onto PERC...I specifically asked the Dell helpless desk if any of the 6is were compatible w/ the 690, and was told outright no.  Course I didn't ask 'will it work,' and hadn't stumbled across the above thread on overclock.net.  I'll dig into that a bit more this evening before I ask something that's already been answered.  Since the PERCs only need 8x it could work, but I wonder if it splits the 8x into 2 by 4x on the 8 pins you're using, and if you can stagger the cards to  or if you c

I totally agree on the coost/gb of SSD, hence the reason for the 3x73gb in RAID-0!  I was trying to balance speed with storage (and cost); less than the best of both worlds I guess.  Let me know if it ends up working for you

THANK YOU FOR THE PICS!

You are welcome :)

Onto PERC...I specifically asked the Dell helpless desk if any of the 6is were compatible w/ the 690, and was told outright no.  Course I didn't ask 'will it work,' and hadn't stumbled across the above thread on overclock.net.  I'll dig into that a bit more this evening before I ask something that's already been answered.  Since the PERCs only need 8x it could work, but I wonder if it splits the 8x into 2 by 4x on the 8 pins you're using, and if you can stagger the cards to  or if you c I totally agree on the coost/gb of SSD, hence the reason for the 3x73gb in RAID-0!  I was trying to balance speed with storage (and cost); less than the best of both worlds I guess.  Let me know if it ends up working for you

PERC 5/6 should work in ANY PC - sometimes you'll need to cover pins 5 and 6 - "pinmod" ;) Some motherboards won't work with PERC 5/6 - but they are rare.

There is no reason to put PERC 5/6 into PCI-e x4 as you will lose performance ...

Interesting...on the Perc 5/6 performance, why the heck would Dell build a machine that is SLI & RAID 5 capable, but not put in a PCIe 16x slot in place of the #24 PCIe 8x slot???  Now I see why you're asking the question, which makes me wonder whether you can run a PERC 6i off the riser @ 32 bit speeds on one channel and another VC off the other channel?  Please let me know if it works because knowing that makes me think the dual VCs in SLI will to end up getting replaced down the road with a more current VC and a PERC!  

Also, back to the power issue; there's an unused 6 pin coming out of the 750w PSU; I have to check it tonight, but I'd bet this is for the riser (orange, yellow & black) and the upper VC (blue), with the lower powered by the other PCIe

Robinet,

I am in the process of replacing the video card in my Dell P690 w/ 1000W PS with a GeForce GTX 580.  This card/device requires both 6-pin PEG and 8-pin PCIe PEG connection for power.  I will use P5 (or P10) for the 6-pin, but P11 does not appear to be a PCIe PEG connector.  Do you know what type of connector it is?  And, would you happen to know if an adapter exists to convert (pinout) to a PCIe PEG?

Thanks,

Mark -

Hi MSquires,

Maybe this will help you:

www.overclock.net/.../5870-eyefinity-6-500w-psu

You can find exactly the same converter on eBay.

cheers

Robinet,

Thanks again for the help, the wiring harness worked like a champ!  Also, after seeing the pics i realized that the T7400 manual actually has pinouts, and they did appear to match for my purposes.  It's worth a look...Thanks again!

You are welcome :)

Robinet,

Thank you.  Are you recommending that I connect the adapter (photo above from the link you provided) to one of the PSU 6-Pin (P5 or P10) connecters?  Or, is there an 8-pin (P11) to 8-pin PCIe PEG adapter available also?

Thanks,

Mark -

Hi Mark,

As the P5 and P10 connectors should be universal - to use with ANY PCI-E graphics card - and the cable from the photo is also universal - you should be able to use it as converter from 6pin to 8pin - but I haven't tried it myself so I can't give you any warranty :( but I would use it that way ;)

cheers

MSquires,

If your video card is keyed to accept that connector you MAY be okay, but dell's 8 pin plug runs comm, 3.3vdc and 12vdc.  Check the pinout on your card against the t7400's p5 and p19 connectors.  I had to make a custom harness for my setup, but it was because the riser card needed the 3.3vdc connection.  Your card may run a standard configuration just be sure the input from your psu is pushing the correct power to each of your pins.

<ADMIN NOTE: Broken link has been removed from this post by Dell>