ATI Radeon 4870 X2--Power Supply?

[BoeingGuy 0]

Hi all,I'm researching buying a 4870 X2 since all MS games will run better that way. Will I need a better PSU/Power Supply, seeing as the 4870 X2 consumes 245 more watts than the 8800 GT?Thanks!

[Guest UlfB]

Hi,A review here: http://www.hardocp.com/article.html?art=MT...GhlbnRodXNpYXN0And another here:http://www.anandtech.com/video/showdoc.aspx?i=3354&p=8You could estimate the power needed by these reviews. I'm not familiar with your PSU, but if it's able to keep up 600W it should be OK.Ulf BCore2Duo X6800 3.3GHz4GB RAM Corsair XMS2-8500C5BFG 8800GTX, Creative SB X-FiFSX Acc/SP2, Vista 32

[Guest djt01]

>Hi all,>I'm researching buying a 4870 X2 since all MS games will run>better that way. Interesting, how did you come to that conclusion?

[Noel 4,486]

Hi Boeinguy,I'm wondering now about just how much overkill we are doing now with powersupplies. I used two different suggested PS configurators to determine what I needed for my current rig:QX9650@4.2Gh/1.4125v vCore2 15K.3 SCSI drives2 SATA 3Gb/s drives4GB DDR38800GT/OC to 7004 fans2 optical drivesNow, add this:Alesis powered 8 Channel mixerRoland A90Ex stage pianoKorg Wavestation A/D sound module4 port powered USB hubNow here's the clincher: recently I bought a 1,500W APC UPS which displays load in watts. When I am running FSX full tilt, fully overclocked, THE SUCKER SHOWS 320W, that's it! That's absolute peak. It's usually bouncing around between 290 and 305W.So, why the heck did I buy a 750W PS? I think the recommendations on wattage rating for PC powersupplies represents serious overkill, unless I am missing something in this. Perhaps the LCD on this new APC UPS is bogus, I don't know. Can't see any reason why I can't run 4870 x2 so just may. The FPS drop is troublesome though compared to my 8800GT. I'd love the headroom for first person shooters, but be a drag to take a hit in FSX.NoelQX9650 w/ Retail HSF|ASUS P5E3 Premium WiFi|4GB Muskin Ascent 7-6-6-18 1T DDR3-1600|EVGA 8800GT|Seagate SATA 2 x 2|Seagate Cheetah 15K.x|XP Pro SP2|Vista 64--maybe never to be installed

[Guest UlfB]

>So, why the heck did I buy a 750W PS?Maybe because your PSU isn't able of delivering 750W continuously? What model do you use?You would increase the load about 200W when going from a 8800GT to the 4870 X2. http://www.anandtech.com/video/showdoc.aspx?i=3354&p=8I would never purchase a PSU that's barely able to deliver the watts and amps needed. I would go for a lot of headroom and having the PSU to performe well without any risk for overheating. If you did buy a 500W PSU, you would have to replace it if you would go for a 4870 X2. IMO a 750W PSU isn't overkill.Ulf BCore2Duo X6800 3.3GHz4GB RAM Corsair XMS2-8500C5BFG 8800GTX, Creative SB X-FiFSX Acc/SP2, Vista 32

[Reset XPDR 1,271]

I agree. I fail to see how any single card graphics solution system needs any more than 500W quality power supplied, yet people around here talk of 1000W+ supplies to handle "the load" on such systems. I manage to survive on "only" a 480W PSU with my system.Gary

[Guest UlfB]

>I agree. I fail to see how any single card graphics solution>system needs any more than 500W quality power supplied, yet>people around here talk of 1000W+ supplies to handle "the>load" on such systems. I manage to survive on "only" a 480W>PSU with my system.>>GaryMy guess is that you wouldn't survive with the 4870 X2.Ulf BCore2Duo X6800 3.3GHz4GB RAM Corsair XMS2-8500C5BFG 8800GTX, Creative SB X-FiFSX Acc/SP2, Vista 32

[BoeingGuy 0]

Thanks for the replies guys, for now I'm sticking with the 8800 GT.Djt, I came to that not-so-fixed conclusion because ATi drivers don't seem to have a problem with MS games. NVIDIA seems to be constantly plagued by driver errors when it comes to MS games.Well that's what happened to me. An unstable overclock that I failed to notice/test caused my card to keep crashing. Lowering the Core/Shader/Mem clocks by 20 MHz stabilized everything again.Cheers,

[Noel 4,486]

>>So, why the heck did I buy a 750W PS?>>Maybe because your PSU isn't able of delivering 750W>continuously? What model do you use?>>You would increase the load about 200W when going from a>8800GT to the 4870 X2.>http://www.anandtech.com/video/showdoc.aspx?i=3354&p=8>>I would never purchase a PSU that's barely able to deliver the>watts and amps needed. I would go for a lot of headroom and>having the PSU to performe well without any risk for>overheating. If you did buy a 500W PSU, you would have to>replace it if you would go for a 4870 X2. IMO a 750W PSU isn't>overkill.Ulf, I bought the thing because the configurator, and many comments in here, suggested this is what is needed. I question this now. I have allegedly one of the best PS available, a PC Power n Cooling 750W with big 12v rail. With my very overclocked PC, and MULTIPLE other pieces of hardware connected, I don't even get to 50% of the rated capacity. I maintain it's overkill that has come from people using configurators and from all the other "knowledge" in forums such as this, where people have good intentions but may really not know what they are talking about from an electrical engineering standpoint. Even so, it's chump change to buy a 750W PS :()

[Guest UlfB]

Noel,I get your point. I'm no expert so I trust you being right on this one. But I still have a feeling that you should have headroom between your actual peak load and the PSU peak capacity. Is this a mistake by me?Ulf BCore2Duo X6800 3.3GHz4GB RAM Corsair XMS2-8500C5BFG 8800GTX, Creative SB X-FiFSX Acc/SP2, Vista 32

[nigelgrant 4]

One of the most important things today with power supplies is the ability of the 12v rail(s) to meet the demand of the GPU or other hardware. I know - I have a Sapphire ATI X1950XT which draws 30 amp at 12v, my PSU gave 18A on each of two 12v rails so I kept having crashes. I now have a PSU which gives 54 amps on a single 12v rail and things work fine. Except I am a bit concerned now that the previous under-supply might have damaged my GPU, which apparently can happen.So the new moral is that the total wattage is not necessarily the best paramater to look at. Lots of good info on this topic at the Sapphire forum. http://www.sapphiretech.com/en/forums/forumdisplay.php?f=4NigelVancouver

[Noel 4,486]

>Noel,>>I get your point. I'm no expert so I trust you being right on>this one. But I still have a feeling that you should have>headroom between your actual peak load and the PSU peak>capacity. Is this a mistake by me?>>Ulf BSure, headroom sounds wise. But 120% headroom? Remember, with the numbers I gave, this is a penryn and 8800 overclocked significantly, so the headroom was their bigtime. Anyway, I only bring it up for this who believe they need to go buy a 1,000W PS if they add an X2 video card, or even in crossfire. It appears I can install TWO X2 cards and still have breathing room.QX9650 w/ Retail HSF|ASUS P5E3 Premium WiFi|4GB Muskin Ascent 7-6-6-18 1T DDR3-1600|EVGA 8800GT|Seagate SATA 2 x 2|Seagate Cheetah 15K.x|XP Pro SP2|Vista 64--maybe never to be installed

[Noel 4,486]

>One of the most important things today with power supplies is>the ability of the 12v rail(s) to meet the demand of the GPU>or other hardware. >>I know - I have a Sapphire ATI X1950XT which draws 30 amp at>12v, my PSU gave 18A on each of two 12v rails so I kept having>crashes. I now have a PSU which gives 54 amps on a single>12v rail and things work fine. Except I am a bit concerned>now that the previous under-supply might have damaged my GPU,>which apparently can happen.>>So the new moral is that the total wattage is not necessarily>the best paramater to look at. This is my understanding as well, so this is why I bought one with a 60A 12v rail, or thereabouts.

[Guest djt01]

>Djt, I came to that not-so-fixed conclusion because ATi>drivers don't seem to have a problem with MS games. NVIDIA>seems to be constantly plagued by driver errors when it comes>to MS games.I

[Guest UlfB]

>>Sure, headroom sounds wise. But 120% headroom? Remember,>with the numbers I gave, this is a penryn and 8800 overclocked>significantly, so the headroom was their bigtime. Anyway, I>only bring it up for this who believe they need to go buy a>1,000W PS if they add an X2 video card, or even in crossfire. >It appears I can install TWO X2 cards and still have breathing>room.>Well, my discussion was about adding a 4870 X2 to a pc, which was the OP's question. You would probably end up with your system peaking between 520W and 560W.I quote my first response to your original post:>Maybe because your PSU isn't able of delivering 750W continuously? >What model do you use?>You would increase the load about 200W when going from a 8800GT to >the 4870 X2. http://www.anandtech.com/video/showdoc.aspx?i=3354&p=8>I would never purchase a PSU that's barely able to deliver the watts >and amps needed. I would go for a lot of headroom and having the PSU >to performe well without any risk for overheating. If you did buy a >500W PSU, you would have to replace it if you would go for a 4870 >X2. IMO a 750W PSU isn't overkill.I totally agree that using a 750W with your present config with a 8800GT is overkill.Ulf BCore2Duo X6800 3.3GHz4GB RAM Corsair XMS2-8500C5BFG 8800GTX, Creative SB X-FiFSX Acc/SP2, Vista 32