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    Hi there,

    I think the time has come to get another Geforce 7800GT for my PC so I can continue gaming at high quality. Despite the GT being quite rare, there are usually a few going on ebay and they're always going cheap. My question is, can I get one made by, say, Leadtek, to work with my Gigabyte one? I've been out of the hardware loop for a while, but last time I was 'in the know' you could only have two identical cards by the same manufacturer running in SLI, has that changed now? Can i get like an XFX one and run it wiht my Gigabyte one providing they're both 7800GT's? Would I have to clock them both the same memory and core wise?

    Also, can anyone say whether I would need a bigger PSU? My current one is 480watt, made by Antec I think. On it I run an Athlon 64 4400+ X2, an ASUS A8N SLI Mobo, 2 gig o memory and a 250gig WD HD, along with the 7800GT. With those components in mind, would adding another gfx mean id need to up my PSU to like 530watts, or even more? If I do need a new PSU too, ill probably get like a 700watt beast so i can run 8800's and stuff in the future without spashing out on one again, it always feels a waste blowing 60-70 quid on a PSU.

    Cheers.
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    Firstly, why do you need the second card? Is it because you run games at extreme resolution and experience slowdown, or because your existing card is just not cutting the mustard enough to run the latest games?

    As far as I am aware... it should work, but if one is clocked faster than the other, the faster card will throttle back to operate at the slower speed. The only constraint is that it must be an identical GPU - so anything of the same model (in this case - 7800GT) should work fine.

    [EDIT] http://en.wikipedia.org/wiki/Scalabl...erface#Caveats
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    cutting mustard to run latests, plus i like playing in high detail, pointless buying 'latest' game if you cant look at what makes it 'lastest'. Plus, 7800GT's are dirt cheap now the 8 series is pretty established.

    excellent, cheers. So i wont need to manually change, it just will anyway?
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    (Original post by Consie)
    cutting mustard to run latests, plus i like playing in high detail, pointless buying 'latest' game if you cant look at what makes it 'lastest'. Plus, 7800GT's are dirt cheap now the 8 series is pretty established.

    excellent, cheers. So i wont need to manually change, it just will anyway?
    I totally agree.
    The problem is, SLi only really yields any significant benefits at higher resolution. You might be better off saving up a few pennies and just getting a decent 8x00 series card.
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    7800gt in SLI isnt great to be honest and you will definiteky not be playing the latest games in max detail. As suggested, itd be better to save up for an 8800gts.

    It may even be better to sell your 7800gt for ~£60 and buy an x1950xt for £100. ANother reason being SLI drivers arent perfect.
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    so my performance wont be doubled? or at least gone up by 50 or 60%?
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    7800GT SLI = 7900GTX < x1950xt < x1950xtx < 7950gx2 < 8800gts

    http://www.hard**********/showthread.php?t=1046381

    Interesting debate. Remember that an x1950xt is better than a x1900xtx.

    edit: the stars should contain "f o r u m.com" without spaces

    http://www.anandtech.com/video/showdoc.aspx?i=2717&p=6
    http://www.anandtech.com/video/showdoc.aspx?i=2717&p=7
    http://www.anandtech.com/video/showdoc.aspx?i=2717&p=8
    http://www.anandtech.com/video/showdoc.aspx?i=2717&p=9
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    7900GTX still cuts it at high settings unless you want like x12 antialaisising though doesnt it?
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    (Original post by Consie)
    7900GTX still cuts it at high settings unless you want like x12 antialaisising though doesnt it?
    Yes it does. However, i just thought the x1950xt upgrade route might be better.
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    ah yes. It would run fine (given its PCiE) on my A8n mobo wont it? What's its power requirements? Less/more than the 7800GT? What percentage faster is one of the x1950xt compared to the 7800GT exacly? And would an sLi 7800GT beat a single x1950xt? I wont be able to do the crossfire thing with two x1950xt's becasue i have a nvidia sli mobo, is this assumption correct?
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    SLI 7800gt may beat the x1950xt in nvidia favoured games such as doom 3 and quake iv, but otherwise the x1950xt (512mb) will be better.

    I dont think youd want to go crossfire in the future anyway right? So that doesnt matter.

    Power requirements of 7800gt in sli and x1950xt should be similar. Basically a 450w PSU with 30A on the 12v rail should suffice.
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    cheers for the info homeboy. How much you think is a good price for them on e.g. ebay?
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    Let me just inform you of the benefits and drawbacks of SLI, as nobody else has.

    If you run at less than 1600x1200, 1920x1080, or 1920x1200, SLI will do nothing. absolutely diddley squat.
    At or about those resolutions, the increase is between 30-40% at the absolute most.

    So if you don't run at those resolutions, SLI is a waste of time and money.

    If you do, a more powerful single card may still be better than a second card of what you already own.
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    why is this the case man?
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    because that's what SLI was designed for. To improve performance in ultra high resolution situations where 1 card began to slow. but the improvement isn't even 50% because it's not a particularly efficient process.
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    why my resolution size is capped at 1280/1024 ive never been able to understand. I have a single 19 inch monitor, could i get higher resolutions? Especially if i had two cards?
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    (Original post by olileauk)
    If you run at less than 1600x1200, 1920x1080, or 1920x1200, SLI will do nothing. absolutely diddley squat.
    This is incorrect.

    Using two 7800gts instead of 1 will have marked improvements over a single GT. Why? Because instead of 20 pixel pipelines, now it has 40 pixel pipelines at its disposal. SLI in XP is very good at scaling and without CPU limitations, can see improvements of around 60%. 40 pixel pipelines over 20 will give benefits at every resolution w/o CPU limitation. There are diminishing improvements to scale even with single cards so i take this argument to be flawed. However, as suggested above, drivers arent as refined.

    SLI gaming was indeed created for ultra high resolutions for the latest game at when the games came out. However, it was also created for scenario's exactly like the OPs where it allows a cheap upgrade path.

    "SLI is a waste of time and money" - No actually its the cheapest option out of those available and gives comparable performance to a 7900GTX/x1950xt.

    (Original post by Consie)
    why my resolution size is capped at 1280/1024 ive never been able to understand. I have a single 19 inch monitor, could i get higher resolutions? Especially if i had two cards?
    No, your monitor can only handle 1280*1024.
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    (Original post by Jaffaholic)
    This is incorrect.

    Using two 7800gts instead of 1 will have marked improvements over a single GT. Why? Because instead of 20 pixel pipelines, now it has 40 pixel pipelines at its disposal. SLI in XP is very good at scaling and without CPU limitations, can see improvements of around 60%. 40 pixel pipelines over 20 will give benefits at every resolution w/o CPU limitation. There are diminishing improvements to scale even with single cards so i take this argument to be flawed. However, as suggested above, drivers arent as refined.

    SLI gaming was indeed created for ultra high resolutions for the latest game at when the games came out. However, it was also created for scenario's exactly like the OPs where it allows a cheap upgrade path.

    "SLI is a waste of time and money" - No actually its the cheapest option out of those available and gives comparable performance to a 7900GTX/x1950xt.



    No, your monitor can only handle 1280*1024.
    But it doesn't provide a linear increase in perfomance - ie. 2x GPU = 2x performance. Nowhere near.
    Instead you're just paying more money for obsolete hardware, which, at the point of upgrade, you're going to have 2 VERY obsolete cards worth zilch to get rid of, when the better solution would be to sell the current card for a decent sum of money and upgrade to a better overall card. This way, you aren't left with tonnes of worthless legacy hardware lying around when you come to upgrade.
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    I'd be careful with the power consumption, too. You say that you don't want to waste £60 on a decent PSU, but you need a decent PSU. I bought a 1900xt last year and needed to buy a new PSU. The specs on the box for the card say it needs 29A on the 12v rail, and my half decent 500w PSU only just has enough (32A I think). It's a power hungry card, but then again it's only 1 card whereas SLi is two, and you may need a better PSU. Just thought I'd warn you.
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    how much better is a 1950xtx than a 1950xt?

    would it be better to buy an 8800GTS? i.e. with only 320 memory? they cost about 210 quid new i think.
 
 
 
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