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Odd advice from tech support

Angilion

Angilion

Angilion

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Tech support for a company I won't name has been getting a fair few calls about their 7800GT cards. There is an unusual amount of instability issues and the 100% fan speed issue seems universal on some revisions of their cards. I've found one claim of working fan control on these revisions.

Anyway, here's some great advice from that company's tech support about the stability issue:

i) You must have a PSU that supplies at least 25A on a single 12V rail. PSUs with dual 12V lines probably won't work properly with these cards.

ii) DX9-based games will run fine with the card at stock speeds, but you will have to underclock it to run OpenGL-based games stably.

Gotta laugh, I suppose.
 
<goes off to play Doom 3 on his overclocked 7800GT with working fan speed control running off a dual rail PSU (18amps and 16 amps) :p
 
25A is a large amount of current - I don't believe the guage of molex wires used in PCs can handle that tbh... certainly sounds a bit fishy. I think you'd need 12AWG wire.
 
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i wish you would name the company tbh...

there are going to be loads of paranoid 7800GT users now :p

*strokes his trusty old but gold 6600GT*











*looks scared at his new box with a 7800GT in it*
:o
 
Good point, nikebee. It's XFX. Personally, I think that their tech support is flakey. I see no reason why a PSU with 2 12V rails can't work properly with a 7800GT. I also think their products are flakey - the use of a molex connector on a PCI-E card is odd and the UDE* revision cards seem to be throwing up more problems than is normal, especially the lack of fan speed control. I have not seen a single claim of the UDER revision having working fan speed control at all - does anyone here have such a thing?

It is even being considered (on XFX's forums, at least until they delete the thread) that the versions of the cards with lots of LEDs don't have fan control at all. The LEDs are powered from the same wires as the fan (a simple split after the power header) and the LEDs require 12V. Metering shows 12V being supplied to the fan at all times.

Daz...my PSU is spec'd for 26A on a single 12V line, so it is possible. It won't all be going over the same wire, so the guage is heavy enough. The recommended limit in the ATX spec is 18A per 12V rail, though.
 
I have just bought a XFX 7800GT and have a Enermax PSU with two 12V rails :(

I have changed the retail fan for a Zalman VF700-Cu and that runs of the PSU so I think I will be fine or is there another problem :confused:

I can't use my machine as my memory is RMA'd and I have no CPU yet.
 
Dutch, erm I seriously doubt you have anything to worry about. Mine is going fine on a dual rail PSU, overclocked and on stock cooling without issue as are many others.
 
Raikiri...do you have working fan speed control on a UDE3, UDE7 or UDER revision card? I'm trying to find out if it's possible.
 
Dutch Guy said:
I have just bought a XFX 7800GT and have a Enermax PSU with two 12V rails :(

I have changed the retail fan for a Zalman VF700-Cu and that runs of the PSU so I think I will be fine or is there another problem :confused:

I can't use my machine as my memory is RMA'd and I have no CPU yet.
Click to expand...

Power-wise, I think the only thing you'll have to watch out for is how you connect components that use a molex connector, if you have the XFX 7800GT revision that uses a molex connector rather than the standard PCI-E power connector. If you have a version with the standard PCI-E power connector, I doubt if that would be a problem as long as your PSU has enough power output for the two 12V rails combined.

If you have the molex version, it would be a good idea to not have anything else on a molex connector on the same cable as the one you put in the card. 18AWG cable (which is probably what you have for your Molex connectors from your PSU) plus PCI-E slot can supply enough power for an o/c 7800GT card with some LEDs on it, but there isn't much left over. Having anything else powered from the same cable, unless it uses very little power, might cause stability issues.
 
Angilion said:
If you have the molex version, it would be a good idea to not have anything else on a molex connector on the same cable as the one you put in the card. 18AWG cable (which is probably what you have for your Molex connectors from your PSU) plus PCI-E slot can supply enough power for an o/c 7800GT card with some LEDs on it, but there isn't much left over. Having anything else powered from the same cable, unless it uses very little power, might cause stability issues.
Click to expand...
I have a card with a molex connector, but I also have a dedicated molex connector coming from my Enermax PSU so I guess (hope) it will be okay
 
I have just RMA'd a XTX 7800GT LED Extreme Edition. It has a molex connector on the card. I was seeing corruption in the BIOS screen, windows install and 3DMark06/3D games.
PSU is an Antec Smartpower 400W. Hope it wasn't just a lack of power.
 
Perplexed said:
I have just RMA'd a XTX 7800GT LED Extreme Edition. It has a molex connector on the card. I was seeing corruption in the BIOS screen, windows install and 3DMark06/3D games.
PSU is an Antec Smartpower 400W. Hope it wasn't just a lack of power.
Click to expand...
Ouch, that is also my card and I installed a Zalman VF700 before testing the card, time to cross my fingers and hope for the best :o
 
You might like to look over on XFX's forums. The main thread about the most common problem (no fan speed control) was deleted by XFX, but there are many others.
Most people seem to be circumventing the 100% fan speed on the XFX 7800GT Extreme Noise Edition in the way you did - fitting another cooler.

This should cheer you up a bit, Dutch Guy - there are very few stability/artefacting/etc issues being reported with the UDER revision. Almost all the people reporting them have the UDE7 revision.
 
Angilion said:
This should cheer you up a bit, Dutch Guy - there are very few stability/artefacting/etc issues being reported with the UDER revision. Almost all the people reporting them have the UDE7 revision.
Click to expand...
Just checked and I do have a UDER revision card.

I just wish my memory and CPU would turn up so I can fire it up :(
 
ARGH!

Paranoid now, LOL

I have the UDF7 v1.2 revision, how about this one?

Have to admit, I was curious about the power arrangements for this board.

Has a 6 pin plug on the board (doa ALL PCIe gfx cards need this???) which goes to TWO molex connectors....

It makes sense to me that they should go to different rails of the PSU or else there is no need to have two of them. (No, it's isnt a molex pass through, they are both male connectors)

Manual is pointless and doesn't mention even making sure they are both connected.

I have it overclocked and it runs benchies fine, not had a chance to play HL2 or anything yet.

Running off an Enermax EG465AX.............33amps on 12v rail. :)

As for the fan speed stuff.............it gets slightly louder as it warms up during benching and is loud until windows boots up so I think all that is working ok?

Or do I misunderstand?
 
I think the issue with fan speed is that the card stays as loud as it is when booting, if your fan slows down when the driver is loaded your card is fine.
 
Dutch Guy said:
I think the issue with fan speed is that the card stays as loud as it is when booting, if your fan slows down when the driver is loaded your card is fine.
Click to expand...

Cheers. :)

Just been on the XFX forums and looks like my revision is a "good" one luckily.

Ie.

UDF7 1.2

.12 bios

6 pin PCI-e rather than molex

Fan controller works.

All seems ok anyway. :)
 
Yes, there are very few complaints about that version, just the odd few you'd expect from anything. It's the UDE models that have an unusual number of problems. What is odd is that UDE7 and UDER models are newer than the UDF7 model, so XFX have introduced problems rather than fixing problems.
 
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