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Which graphics card for Optiplex 755?


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Which graphics card for Optiplex 755?

  • I've read some interesting things lately, like "gamers don't buy workstations," and there's really not much difference between a high-end workstation graphics card and a high-end gamer card, except stabile drivers, the ability to render OpenGL, and the price, the price, the price!


    Well, I like the stability, longevity, and support of a business computer, so here I am with an Optiplex 755 w/ Wolfedale E8400 Core duo 3.0MHz, 6M L2 cache, 1333 FS bus. It came with 667 MHz memory instead of 800, but seems like 667 DDR should be able to feed the 1333 FSB well enough. I just upgraded to the max 4G RAM w/ 32bit XP Pro. Not too bad a machine, until I investigated putting in a graphics card. I should say that I am not a gamer, but would like to try some games, maybe FlightSim. I  plan to do video editing of family videos, and I want quality output and fast processing. I have been known to dabble at being a hardware geek from time to time.


    I knew that the PCIE-16 slot was version 1.0, so operates at 1/2 the speed of 2.0. I somehow thought the graphics card would determine the speed, but that was a pipe dream. Someone told me PCIE 2.0 cards would not work at all with a 1.0 interface. (There's also only 1 slot, so no Crossfire or SLI.)


    So I started looking at about the fastest PCIE 1.0 gaming cards, the 8800 GTS 320M and 640M. However, I'm worried about 2 basic things - fitting the card in the machine, and not frying the machine. The slot in itself is marked 75 W. All the graphics card reviews I've seen lately start at 130W power consumption at idle and go up to perhaps 250W+ at load. What gives? Can someone please explain to me what the Optiplex 755 PCIE-16 75W restriction means, and how I know which cards satisfy it.


    Also, I came to realize after a while and reading some post here that the mobo is effectively upside down in the Optiplex 755 mini-tower. If you look from the front of the computer, almost all the time - all other Dell's and most computers I've seen - the motherboard is on the right. In the Optiplex 755 it's on the left! This means that the graphics card has to go face up in the PCIE slot. That in itself makes more sense, that hot air should rise off of the heat sink, instead of getting trapped under the board (see Zalman heat sink solutions). However, the Dell engineers put the PCIE slot at the top of the expansion slots. That means no double-height cards, which are better cooled. There is also the enormous CPU heat sink/fan shroud and relatively shallow case, which makes it probably impossible to get a 9 or 10 in. card in the machine. Goodbye 8800 GTS (unless it could fit and there are single height ones - prob 320MB - that run cool enough)? Opinions, please!


    I did find an excellent bargain in a workstation card - ATI FireGL V7200 - with total memory bandwidth 40GB/s+ and with a removable card extension, so the length of the card would be good. But guess what, it's double height! If only there was a way to hack off the grilled second slot cover, or somehow bend it to fit in the case without voiding the warrantee! Very frustrating!


    So it looks like I'm stuck with the 8600 GTS, unless someone can tell me otherwise - please! 512M GDDR3 is important, but total memory bandwidth is key - at 32Gbytes/sec, at least it's half that of the 8800 GTS.

    So the next concern is the heat dissipation. When the heat comes off the graphics card, hopefully it will drift away from the CPU and not get drawn by the CPU fan over the CPU heat sink! Or rise to kill my memory cards! What's your opinion on this worry? Should I/can I put a case fan nearly opposite the CPU fan? Talk about cross-purposes! What about an expansion slot fan? Underneath the graphics card, I'm not sure how much good it would do.


    I did find the solution to the power supply. It's a PC Power and Cooling 500W special Dell edition, with 2 metal slots that are required to support the PSU from the top of the case. I don't think it's possible to suspend the power supply just from the screws? So that limits your choice of PSU. I had looked at other PSUs, like OCZ / StealthXStream / 600-Watt, but I wonder if that will be suspended correctly. Also, maybe the PSU fan on the bottom of it would be a good thing? - drawing the hot air from on top of the graphics card into the PSU? Maybe a bad thing, but case airflow in general is supposed to be good.


    Then again, if I get the 8600 GTS, I may not need a new PSU. I found a post here that says the 305W one I have has 12V rating of 18A. Oh well, 8600 GTS needs 30A. BTW, is XFX a good card? - that looks like what I'm headed for - lifetime warranty! I guess EVGA is an alternative, but I can't find an EVGA 8600 GTS 512MB DDR3 cheap.


    I'm eager to hear feedback and suggestions on a graphics card - under $200, please! Thanks.


  • Replying to my own post, since I just got a great email from the EVGA sales support team. The 75W is the max power supplied through the PCIE-16 bus. The rest of the power must come directly from the PSU - that's why there is a special 6-pin PCIE power connector. So this is not a concern. Thanks, EVGA!


    But I'm still confused on the PCIE-16 1.0 vs. 2.0 standard. Can someone definitively answer the question on what happens when you plug a 2.0 graphics card into a 1.0 slot? Will it work at half the speed? Will it work at all?

  • Putting a PCIe 2.0 16x card in a PCIe 1.0/1.1 16x slot gives it half the bandwidth. However, even the fastest cards out there at this time can't get close to filling the whole bandwidth, so it's not really an issue. I'd be surprised if it would be any noticeable difference in performance.

    You may need to upgrade the powersupply if it's a pretty high end (high power requirements) videocard. Usually the Dell powersupply is ok (underrated), but a card like a GTX280 or 4870 may just require a bit too much.

    Member since 2003

  • Thanks very much for your answer. I'm relieved from at least the compatibility standpoint that I have a lot more and better choices than I thought.


    So that leaves fitting in the case and heat dissipation. Regarding heat, maybe I posed a lot of silly worries in my original post. Maybe the Dell engineers were really smart, and the heat coming off the graphics card being drawn through the CPU fan is how they designed it. A strong airflow from the back to the front of the case is what will happen.


    I'm just concerned that 70 or even 80 Centigrade hot air being generated from the graphics card will fry something - CPU, memory, or mobo. You do hear a lot of horror stories out there about cards running hot. One possibility I've heard a lot of if the card runs too hot: To break off the cooling mechanism that comes with the card and install a better one.


    It would be nice to have a little more clearance under the CPU fan shroud, and a slot opening in the back with no connector above the PCIE-16 slot, just to accommodate double-height cards. Will virtually all single-height cards fit into the Optiplex 755? What cards have you heard of people putting into this machine without frying it?

    Regarding PSUs: I will probably go with the PC Power&Cooling 500W Dell model. I don't think there are choices out there with more power that are pre-built to go into Dell's. However, with 35A @ 12V, it has quite a bit of power.


    So putting it all together - I want the fastest, coolest-running single-slot graphics card under $200 for my 755. Does ATI tend to run cooler than nVidia? Because of good EVGA technical communications so far, plus lifetime warrantee, I wouldn't mind going with them, and of course they are nVidia.

  • Video cards cannot be too "thick" towards the right end of the card because the heatsink is in the way. So while any PCIe video card will work, NOT ALL WILL FIT.


    It's a matter of finding the right one, but if you ask me, single slot video cards that don't have giant heatsinks should work (and fit)

  • Thanks.


    I think I'm going with the SAPPHIRE TOXIC HD 4850. It looks like it will fit and it has a well-rated cooling solution (Zalman VF900). It's a little more money than I want to spend, but it's near state-of-the-art. I will have to wait until it's in stock and also until Linux drivers come out to use the Cinelerra video-editing software that I want to try, whenever I get around to installing Linux.

  • PS - mobo is not upside down, the case is BTX not ATX, and that is how those work, mounting to the other side of the case. :)
  • JoelK, I'm in the same situation wanting to upgrade the video card in my work Optiplex 755. I greatly appreciated reading the info in your posts. What about using a nVidia GTX 260 card? It seems to run cooler and require less power than the ATI 4850. Any problem with it? Also, will I lack a video card power connector with the stock power supply in the Optiplex 755 case? Also, any idea on how to attach a CD_IN audio cable from the DVD burner to the motherboard's integrated sound controller? It seems to be missing on my 755 motherboard. Thanks!
  • After the money and time! I've spent on this, I can't afford the extra $80-100 to buy the GTX 260! Especially when I will have to buy a new power supply - more on that later.
    The 4850 review I saw says it comes in under but close to the GTX 280 in performance - http://www.overclockersclub.com/reviews/sapphire_hd4850
    So that means it's probably on par or above the GTX 260. Please show me where you see the 260 runs cooler. There is supposedly a fix for the fan speed on the 4850 which makes it run cooler -
    Remember the show-stoppers about fitting the graphics card into the case. No double-height (double-slot- cover) cards, no thick cards at the opposite end from the slot cover (usually the right from the top of the card). Also, even a lot of single-height cards have the fan at the right, which is bad - it will be  

    at least partly under the CPU fan shroud. If you break the factory cooling solution off to install something like a Zalman, you will likely void the warrantee.
    Even though the 305W Dell PSU is likely underrated, I think you gotta get a new one, otherwise you're asking for trouble. The published system requirements for these cards definitely indicate that.
    I'm getting too impatient. I'm almost ready to opt for an older-generation solution like the XFX GeForce 8800 GT Video Card - Zalman Edition, or similar BFG OC Thermointelligence. They are a little cheaper, but the performance is quite a bit worse than the 4850. I should wait. 

    BTW, MSI makes a 4850 card with a massive copper & plastic cooling apparatus. Looks like it will block a lot of airflow in the case though, and might just not quite make it in. 

    Still worried about possibly frying my system when I finally get the card. I don't think there's any way to put in another fan, and the hot air's going to go right over the CPU heat sink and out the front, probably burning my leg in the process. I'm too much of a pessimist - maybe it will be OK.


    Can't answer the question about the audio cable now. Gotta get back to work, and can't detach everything and take the cover off to find out (don't remember).

  • Be careful when picking a power supply to upgrade to. Not all fit.


    The one that worked for me is the Antec Earthwatts EA650 PSU

  • I did a lot more research after my first post, and not considering GTX 260 anymore. Please ignore my statement about comparing the heat of HD 4850 and GTX 260. What I was thinking was the total system power consumption at idle, http://www.anandtech.com/video/showdoc.aspx?i=3341&p=22. Anyway, I'm ordering a lower powered Asus 1 Gb 8800 GT in hopes I won't need to replace the 305W PS.
  • If you want the best single slot cards your choices would be either HD4850 or GeForce 8800GT 512MB but I would recommend upgrading the power supply.  The main reason for upgrading power supply would be that the 305W power supply in your system doesn't have a 6-pin PCI-express power cable.


    For a power supply, I would recommend going with a Dell 375W Power Supply that is used in the Precision and XPS systems.  It does have the needed PCI-Express power cable.  I have en extra 375W Power Supply - send me a private message if you might be interested.  Pictures below show an Optiplex 755 with a 375W PS and Geforce 8800GT 512MB.


    Message Edited by jmsandrsn on 08-14-2008 01:16 PM
    Message Edited by jmsandrsn on 08-14-2008 01:17 PM
  • Just thought I'd add to this thread. I realise it's several years old now but still worth an update. Cool

    I got myself an Optiplex 755 Desktop recently and added the PCI-E riser card so that I could use Full-height graphics cards in it.

    I was hoping to use an Inno3d Geforce 9800GT in it, as it is quite powerful (although based on the 8800GT so a little old) but only uses 75W of power so does not need an uprated PSU.

    Sadly the 9800GT is just a shade too long for the case and the end of the PCB fouls on the CPU cooler :(

    I've settled for a Radeon HD5760 which is a little slower than the 9800GT but only uses 65W at peak so does not need the PCI-E power connector and will run nicely on the existing PSU.

    I hope in future we get smaller, low power "Green" versions of some more powerful cards out today :)


  • My Optiplex 755 Gaming / HTPC setup is now complete.

    I've taken a humble Optiplex 755 Desktop chassis, upgraded the RAM to 4gb, upgraded the HD to a 60gb OCZ Vertex 2E Solid State Drive, added a PCI-E full-height riser, and upgraded the graphics card to the maximum possible that would fit into the case. I also upgraded the OS to Windows 7 64bit and fully customised the drivers, settings, power management etc.

    I didn't touch the CPU as it came with an E6550, a 2.33Ghz Core 2 Duo with 4Mb cache and 1333mhz FSB, which is perfectly fine for games and, importantly for my build, only uses 65W of power. 

    I should point out that I made a typo in the above post, and I actually bought an XFX 1GB HD5670, not a "5760", which doesn't exist...

    However, although the 5760 fits the system perfectly and it gave me close to 60FPS in most games at 1920x1080, I wanted to see how far I could push this little Dell system.

    I had wanted an Nvidia card, as I much prefer their drivers, but alas no Nvidia card on the market at the moment with any decent amount of GPU power is small enough to fit this desktop chassis. The 9800GT Green is by far Nvidia's "best" card in this regard and it was a few mm too long.

    So after a *lot* of research, I've ditched my anti-ATI prejudices and upgraded to an 1GB Asus HD5750, which *just* fits into the riser card, and the PSU is *just* powerful enough to run it. The fit is so tight the back of the graphics card PCB actually touches the metal fins of the CPU heatsink, and the wires on the PCI-E power connector have to bend around the heatsink clip. Despite all that, it works flawlessly. No overheating issues so far... In fact I think the air coming from unusual racing-car-shaped cooler on the Asus card has slightly improved my CPU temps.

    To get the required power to the card I've had to disconnect the DVD drive, since after using one of the Sata power connectors to power the SSD there are only three power outputs remaining on the 280W Dell PSU: 1x Floppy, 1x SATA and 1x 4-Pin Molex. I used a Sata-Molex converter to give me 2x Molex, and used a 2x molex->6-pin PCIE converter to power the card.

    The only spare power connector in my case is now a floppy connector, so I guess I'll find something to go in the 5.25 bay that uses that for power, a VFD maybe? Cool

    I've underclocked the card a little, to reduce temps and power draw, as I'm slightly concerned about drawing ~230W (peak) from a 3 year old 280W PSU. The underclock reduces my theoretical peak power draw at full load to about 215W, which I'm happier with.

    Even after underclocking, the 5750 is surprisingly fast, quite a bit faster than the 9800GT Green edtion in fact. It produces great framerates in new games like the Dragon Age 2 Demo and Bulletstorm on "high" graphics settings with DX11 at 1920x1080 Surprise

    The SSD reduces game load times to pratically nothing, and with 4GB of RAM and Win7 x64 the system really flies. My 755 is now truly a gaming PC, and sits quietly and discreetly under my TV in a Dell "Energy Efficient" Desktop case!