XW6600 + GTX 760 ?

[M2G2]

Hi,

I have a question:

Short version:

Will GTX 760 graphic card work with XW6600?

Long version:

I have XW6600, 16GB RAM, 1x E5440, 2x Velociraptor 300GB, DVD, Asus EAH6850, std. 650W PSU - which works flawlessly. I want to replace gfx card with more powerful one, my favourite (best bang for the bucks) is NVidia's GTX 760 (while CPU may bottleneck the machine I intend to keep this card when I'll be eventually replacing XW6600, perhaps I could go SLI then).

Theoretically 650W is more that enough for such a card, but since we have only one 6pin aux power, we need another 6pin (or 8pin) aux from somewhere, probably using Molex adapter. Now let's read XW6600 service manual:

+12 V-D - line used by 6pin PCIe aux and Storage - max. continuos current 12.5A (page 8), which yields 150W. Let's assume some 25W margin for 2x HDD + DVD, it leaves 125W, +75W from PCIe port, totals 200W.

Theoretically GTX760 has TDP of 170W, but all manufacturers factory overclock their cards, +15% more power is typical, sometimes even more. So a card can draw 195W or more - pretty close to the limit. Is this safe?

Alternative: as I have only one CPU, and I'm not going to have another, maybe I can mod the PSU? I mean exchanging line +12VCPU1 (17.5A) with +12V V-D: this would supply (nonexistent) CPU1 with max. 12.5A (instead of 17.5A) and PCIe aux and storage with max. 17.5A (instead of 12.5A), which should give me plenty of headroom.

Do you think it is safe (it obviously requires some soldering, I'm quite confident I can do it right)?

[Skylarking · Accepted solution]

Short version:

Yes...

Long version:

A PCIe video card will draw a maximum of 75W from the PCIe slot and the remainder from the graphics card auxiliary power connectors. Normally a 2x3 connector will provide a further 75W while a 2x4 connector will provide a further 150W. As such, if a graphics card requires 300W, this is provided by 75W from the PCIe slot, 75W from the 2x3 connector and 150W from the 2x4 connector... I think 300W is the max power available to a graphics card according to PCIe slides/specs I have seen...

Now if your graphics card manufacturer indicates the card will draw a max of 170W, then you should need 75W from the PCIe slot and the remaining 95W from either ONE 2x4 auxiliary power connector or TWO 2x3 auxiliary power connectors...

Note that a 6 pin (2x3) auxiliary power connector is not intended to provide 150W safely, only 75W max can safely be provided by such a connector...

If your +12V-D line can safely supply 150W, of which 25W is currently used by your HDD & ODD, then you should be able to wire in TWO 2x3 auxiliary power connectors in this line. Obviously you need to ensure you don't go adding more devices to this line since you may then overload this PSU line...

Now if your PSU supplies 650W and the graphics card needs 170W, then you need to ensure the rest of your system stays within the remaining 480W power budget. That is, the CPU (80W each), memory, HDDs (2x6W each), raid cards (25W), mobo (?W), ODD (6W?) and all other equipment connected to the mobo (including usb devices powered by the mobo) must not consume more than 480W... or you will have odd issues occurring...

So, as long as you stay within the +12 V-D feed power limit and within the PSU's total power limit, all should be OK.

In your case, 480W seems like it enough power for the equipment you have connected, so adding a GTX760 should be OK from a power budget...

But i'm not sure if xw6600 actually supports GTX760 so don't be surprised if some issues pop up... As a hint, if the system doesn't boot, suspect an smbus issues between mobo and card... possible using nail polish on graphics card smbus pins may resolve the issue or setting BIOS legacy support may resolve the issue on later UEFI systems...

Oh, and 'caveat emptor' should you proceed with such mods... that is, don't blame me if you toast your system... 

Good luck..

[M2G2]

Thanks! It's nice to know someone's has verified your reasoning.

It's just the measurements such as this one: http://www.techpowerup.com/reviews/Gigabyte/GeForce_GTX_760_WindForce_OC/25.html that keep me wondering (note the "Maximum" = Furmark power consumption; I've been thinking about Gigabyte because it's readily available and decently priced around the place where I live - but I have no vendor preference).

I guess no one has done the experiment like this before...?

[Skylarking]

I haven't installed GTX760 in a XW6600 so can't say if everything will be 100% without error should you install such a card in your system. But do note that the GTX760 consumers a maximum power in the range 165-215W and an average power of 148W according to your reference. How they measured these figures i haven't checked.

So the question is will you need the extra performance of the GTX760 OC version and will such a card be bottlenecked by your CPU so you wont ever see the max out of this OC card? Also consider how will you be using the card - maximum gaming all day playing the latest games, or occasional gaming of older games as this will impact your actual power requirements.

If, as you seem to have calculated, you can dedicate 200W from the PSU for grahics card needs, then on the very rare occassions when you require 215W for short periods, there should be enough headroom within the HP PSU design to cater for occassional power usage excess. These PSU's are well designed afterall..

So don't be too afraid, simply assess whether it would be wiser to avoid an OC card with it's higher max power needs and associstaed heat output as a non OC card may still meet your needs without the higher power and heat issues.

And FYI, i have a Dell T610 Server with x8 PCIe slot that can only feed 25W max from the PCIe slot itself. Unfortunately this server does not have a x16 PCIe slots, so to be able to use Win7 Aero, or simply play solitare, i had installed a modded 32W PCIe graphics card into this machine, that's 28% over the PCie power budget The mod was simply cutting a notch into the card itself so it would fit into the x8 PCIe slot. Since i don't use the card for heavy 3D grahics taks, i never pull the maximum power of 32W fron the 25W PCIe slot and as such this have been working very well without heat or power issues for well over a year and still going strong.... May be time for a gruntier card though but that would need some more research on how to limit the cards PCIe power draw to ~25W and instead pull more from the cards aux power connector, since i'm limited to x8 PCIe slot... 

[M2G2]

Actually I'm quite certain the CPU will bottleneck the card, at least from time to time (read: on some games) - that's why I intend to keep the card after replacing the xw6600 (although I must admit I'll be missing this machine, of all I've ever had this one is the one closest to the tank).

Buying non-oc-ed card is 1) a bit difficult, as every manufacturer oc-es their cards, and since very few people have problems like me, the standard versions, even when exist, rarely make it to the stores, 2) probably leaves me with stock cooling, which is neither efficient (think card longevity + heating already pretty hot machine) nor silent... however from what I've read recently, you can limit oc (or even decrease it) using std. tools added to virtually every card, so I think I'll try to go that way. Perhaps it means no gaming under Linux (no such tools), but I can live with that. I used to work a lot at home (I tend to work on Linux exclusively), but now I've enough work at work

I'm quite surprised you've cut the card - cutting the connector on the mb seems less invasive and simplier (physically) - but grabbing mere 7-8W (10%) more from PCIe (as in your case) could probably save my day.

Thanks again, will keep you posted.

[Skylarking]

Cutting the card on a old XFX GS 760 i had lying around was a much simpler choice than risking an expensive Dell T610 server mobo

This old passively cooled XFX graphics card works a treat and as such i haven't bothered with an upgrade. Going to a much more powerful graphics card is questionable since i will loose half the 16 lanes by using a x8 PCIe slot. As such I haven't researched what the graphics card sweet spot will be w.r.t. x8 lanes being the limiting factor. Obviously something a little more powerful than the GF760 would be good but an NV GTX780 or an AMD R9-290 x29 would be overkill and probably only ever able to run at 50% capability even if i resolved my 25W PCIe slot limitation. This is an upgrade game for me to play on my Dell T610 on another day

Cheers.

[M2G2]

Hi,

I bought the card yesterday. Machine is running since then, no signs of any trouble, I'm beating it with Unigine's benchmarks and several games (without underclocking it to the std. values) and, according to GPU-Z, it rarely goes past 70% of it's TDP and it's only in benchmarks, in games (not the newest ones I must admit) I have nice smooth 60fps and 40% TDP with around 30% (!) load on GPU - so I think I'm on the safe side at least for now. It seems I need to find something more taxing (perhaps something Frostbite 3-based).

Thanks!

[Chonas]

Hello guys,

Im having kinda the same problems.

Im currently using.

OS: Win 8

CPU: 2xE5430 @ 2.66 GHz

GPU: Sapphire R9 290 PCI-E TRI-X OC

HDD: 1 raptor SATA

RAM: 8x1GB Standard

PSU: Delta 650w edition

I´m wondering is this sufficient for the r9 290? The PSU?

Im currently experiencing black screen when trying to install latest AMD drivers + BETAS.

If i remove one CPU do you think its possible it will run?

What do you think guys HW mod required?

[M2G2]

Judging by 12V layout of the PSU removing second CPU is probably of no use. R9 290 is very power hungry card - I wouldn't dare to put it into my machine. You can try replacing DIMMs with fewer bigger ones, but I doubt it'd make a difference.

Like I said previously, in theory it should be possible to reroute more powerful 12V line from CPU1 to devices, but I haven't tried it, and I would not recommend it: the PSU in XW6600 is the most complicated and densely built PSU I've ever seen, and modding it requires some serious skill. "Kids, don't try this at home!"

As a side note I have recently replaced GTX760 with GTX970 (MSI this time), and it works like a charm.

[M2G2]

Small update:

I'm really glad I didn't mod the psu. I've just got a pair of E5450 on the cheap, and after the swap the whole thing is working beautifully - it's much faster than a single E5440 (phew! surpise...) and absolutely no problems with stability even under extreme - artificial - load (at least so far).