How many graphics cards windows support

[dishwara]

Hi,

I am really confused or don't know what i was.
My question is how many graphic cards windows 7 32 supports, Is 64 bit supports more graphic cards?
or other windows version support more cards?
Or at least which operating supports most graphic cards?
which supports more graphic cards, 32 bit or 64 bit OS?

Also, the graphic cards mean, the number of chips in graphic card or just graphic card itself?

5970 & 6990 have 2 chips, is that mean 2 or 1 for windows or any other OS?

I saw many typed windows only support 4 chips, thats 2 x 5970 or 6990 cards & Linux supports 8 chips, thats 4 x 5970 or 6990.
From where this information came?
I searched internet, but can't able to find number of graphics card an OS supports.

Please some one or more than one, explain me or tell me how many graphics cards an OS supports & also give the link from where you got that information.

I want to build some new mining rigs & confused how many graphic cards can i use in a single pc?

Please me help with your knowledge.
Thanks.

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[niooron]

You need Windows x64, 32 bit windows can only map up to 4GB of memory, and that includes ram, vram and the registers of a lot of devices.

About how many cards it supports, I've seen various posts in other forums about PCs running four 5970s. But I really can't confirm it.

[Mahkul]

Apparently MS never learned from their first mistake "No one will even need more than 640KB of memory".

[dishwara]

so, now i am in the position that 64 bit supports more than 4gb ram so it must support more cards.
Actually my system has 4 gb & windows recognisze 3gb only & then 1gb in graphic card. so totally , 5 gb
windows 7 32 with HD6870.

please i need help to find out maximum number of cards supported by an OS.

please input your datas.

[urizane]

There's a difference between address space for RAM and address space for devices.  I have two GTX 460 1 GB cards in my system, yet they only need address space for 352 MB each (32MB + 256MB + 64MB).  The amount of VRAM on a card does not necessarily need to be all addressable by the CPU.  However, since 704MB of address space is consumed by only two GPUs in my system, a quad 5970 system will need significantly more address space available.  A 32-bit OS of any kind wouldn't be a good way to go.  So if you plan on using 8 GPUs (four 5970s), a 64-bit OS is your best bet.  I haven't heard any kind of limitations on Windows drivers other than Crossfire/SLI only being able to handle 4 GPUs in one linked setup.  If the 5970s run their own built-in Crossfire and aren't linked to any others, they should all be visible to the OS.  OpenCL, on the other hand, may have an issue starting processes on graphics cards that don't have a monitor attached to them.  I saw elsewhere on this forum that somebody had to start up poclbm on one graphics card, unplug the monitor (because they only had one), plug it into the other card and start poclbm on that card.  With four 5970s, that could become quite a hassle.  I believe there's an easier way to do that in Linux, but I'm not sure.

EDIT: I should point out that under Windows, if you go to your device manager, click view, resources by type, you can see all of the address space devices are using.  On my system, even though it's 64-bit, all of the devices are configured to use address space under the 4GB boundary.  Right now, the first 3GB of my 6GB of RAM shows up as [0000000000100000-00000000BFEFFFFF] System board, which chops a very tiny amount (2MB) out of that first 3GB.  The last 3GB is above the 4GB boundary and, apparently, doesn't need to be displayed on my device manager.  As always, your specific setup may vary widely from what I have.

[stellan0r]

*push*

[sirky]

*push*

I know people have 4 on 7x64.

Not sure about 5.

With windows you will need dummy plugs or reg editing to get the cards to show up though.

[Chucksta]

I had 4 on one machine, but had to split it into 2 machines, due to overheating. The heat affected the performance of the cards

Win 7 requires that each gfx card has a monitor plugged into it, it needs to see that the card is in use. You need to fool it into thinking monitors are plugged into them. I managed to get a 6 port KVM (keyboard, video, mouse) switch for £30. Solved the problem nicely

Or, if you have monitors that are in use on other machines, just temporarily plug them into your machine with the multiple cards. Start the computer up, then when you are in windows, just unplug all the monitors you don't need.

[stellan0r]

I know people have 4 on 7x64.

Not sure about 5.

With windows you will need dummy plugs or reg editing to get the cards to show up though.

do you have a link where it shows what and how to regedit?

I had 4 on one machine, but had to split it into 2 machines, due to overheating. The heat affected the performance of the cards

Win 7 requires that each gfx card has a monitor plugged into it, it needs to see that the card is in use. You need to fool it into thinking monitors are plugged into them. I managed to get a 6 port KVM (keyboard, video, mouse) switch for £30. Solved the problem nicely

where did you get that kvm switch? here in germany i can't even find a 6 port kvm, only 4 or 8, and the ones with 8 cost at least 150 euro
and do you actually need to plug a monitor into the switch, or is the switch itself enough to fool the cards?
if I can't find another solution, i could just buy very cheap 2-port kvm's (or just try dummy plugs )

[willphase]

do you have a link where it shows what and how to regedit?

link here:

http://forum.bitcoin.org/index.php?topic=12476.msg173240#msg173240

but I'm pretty sure this won't work tbh... Just buy a resistor per video card - anything around 70 or 80ohm is fine, and then plug it between pins 1 and 6 of your VGA converter plug that came with your card.

W

[stellan0r]

link here:

http://forum.bitcoin.org/index.php?topic=12476.msg173240#msg173240

but I'm pretty sure this won't work tbh... Just buy a resistor per video card - anything around 70 or 80ohm is fine, and then plug it between pins 1 and 6 of your VGA converter plug that came with your card.

W

thanks, but I think you are right - 1,50 Euro Dummy Plugs and one cheap 2-port KVM (to connect two rigs to an actual screen) should work out as long as I am on windows


has anyone tried this trick?

http://blog.zorinaq.com/?e=11

[chungenhung]

I know someone here run 5GPU on Win7.
I have installed 5x 5850 in one board, but the last one would not run OpenCL applications.
If you are using nVidia cards, you can have up to 8GPUs in Win7.

[wol-va-rine]

so, now i am in the position that 64 bit supports more than 4gb ram so it must support more cards.
Actually my system has 4 gb & windows recognisze 3gb only & then 1gb in graphic card. so totally , 5 gb
windows 7 32 with HD6870.

please i need help to find out maximum number of cards supported by an OS.

please input your datas.

memory is not the problem here, you can only physically "fit" so many cards onto a single motherboard, my guess is that 4 cards is the max, and that would be single gpu cards, quad-fire is as high as it goes to date, isn't it...? I don't think you can run four 5970s or 6990s in the same system because they both are 2 gpu cards, I mean you could I guess, but it would be a waste because you could only quad-fire them and that would leave half the cores idle, no...?

also you have to realize that those 4 cards are all gonna pull power from your PSU, a lot of powah, so I hope you have at least a 1kw PSU if you plan on running 4 cards, and not a cheap piece of junk 1kw PSU either, a good one that can output it's rated wattage, those tend to get expensive...

so basically my guess is 4 cores, but I could be wrong...

[kiwiasian]

Guys...ok. A lot of misleading information here.

ALL versions of Windows, of both architectures (x64 and x86) support a maximum of 4 GPUs.

5970 and 6990 are dual GPU cards so...use some common sense.

Linux supports 8 GPUs.

[swusc2]

Ok it's time to settle this argument:

ATI cards in either Windows 7 x64 or x86(i.e. 32bit) only allow a MAXIMUM of 4 GPUS. After the forth it fails to load up drivers for those extra cards.

Nvidia cards for some reason (probably because of drivers or architecture reasons) can actually have a MAXIMUM of 8 GPUS in either Windows 7 x64 or x86. You can look it up online lots of people set up 8 GPU systems for F@H.

Example of 8 GPU Nvidia System:
4xGTX 295

http://www.youtube.com/watch?v=4Q1nfHJOvGY&feature=related

at 7:02 you can tell hes running on Windows XP but for all intensive purposes its the same.