Power Error on 7800GS: do I have a faulty card?

[Griever]

Hello,

Would the experts here please help me? I have a problem with the following card just recently released:

Gainward BLISS GeForce 7800 GT SILENT 512MB GDDR3 TV-Out/Dual DVI (AGP).
[ http://www.theinquirer.net/?article=30502 ]

It is essentially a 20-pipe 7800GT bridged down to AGP.

When running a graphically intensive application (like Oblivion for example) I can play just fine for anywhere between 10-60 minutes or so. But without warning the FPS suddenly drops to unplayable levels and I have to quit the game and restart my computer. After rebooting my machine nVidia System Sentinel pops up with an error telling me that the graphics card is receiving insufficient power. It continues to run very badly until I switch off my computer for a while.

However, my PSU is a newly installed 500W unit [ http://www.qtec.info/products/product.htm?artnr=14321&specs=1 ]. My understanding is that 400W or more should be ample for modern cards. I have the card plugged securely into my motherboard's AGP slot (MSI 865PE) and I have two molex power connections merged into the 6-pin power socket on the 7800GT. The molexs are on a lead supplying the 7800GT exclusively. I've followed the instructions in both my manual and from the nVidia website. Temps are 30-45 for the CPU, 50-80 for the GPU and 35-40 for the system.

Do I have a faulty card?

I really appreciate any information and advice anyone can offer!

 

[linux_0]

Hello,

Would the experts here please help me? I have a problem with the following card just recently released:

Gainward BLISS GeForce 7800 GT SILENT 512MB GDDR3 TV-Out/Dual DVI (AGP).
[ http://www.theinquirer.net/?article=30502 ]

It is essentially a 20-pipe 7800GT bridged down to AGP.

When running a graphically intensive application (like Oblivion for example) I can play just fine for anywhere between 10-60 minutes or so. But without warning the FPS suddenly drops to unplayable levels and I have to quit the game and restart my computer. After rebooting my machine nVidia System Sentinel pops up with an error telling me that the graphics card is receiving insufficient power. It continues to run very badly until I switch off my computer for a while.

However, my PSU is a newly installed 500W unit [ http://www.qtec.info/products/product.htm?artnr=14321&specs=1 ]. My understanding is that 400W or more should be ample for modern cards. I have the card plugged securely into my motherboard's AGP slot (MSI 865PE) and I have two molex power connections merged into the 6-pin power socket on the 7800GT. The molexs are on a lead supplying the 7800GT exclusively. I've followed the instructions in both my manual and from the nVidia website. Temps are 30-45 for the CPU, 50-80 for the GPU and 35-40 for the system.

Do I have a faulty card?

I really appreciate any information and advice anyone can offer!

Generic PSUs are often terrible.

I would suggest getting an ANTEC, OCZ, Silverstone, or PC Power & Cooling PSU.

Your PSU may not be able to provide enough clean power at peak.

An Antec TPII 550 should work a lot better.

http://www.newegg.com/Product/Product.asp?Item=N82E16817103931




I checked the link you posted...... Q-Tec won't even publish the actual specs on the PSU so I am VERY skeptical at this point, it sounds like the PSU cannot provide enough power.

 

[Griever]

Thank you for your post linux_0. The retailer who sold me the Q-Tec assured me it could handle a 7800GT - maybe I need to go and have a word with him...

How about this PSU:
http://www.ebuyer.com/customer/prod...hvd19wcm9kdWN0X292ZXJ2aWV3&product_uid=102953

Does anyone have this PSU? Would it definitely run the card well?

Thanks again!

 

[linux_0]

The OCZ should be quite good :-D

Could you please take a picture of the sticker on the side of the PSU and post it?

Or just post the specs. The website doesn't say which generally means they might claim 15A or more on the 12V rail but might actually only supply 12A or less.

 

[Griever]

I couldn't get my camera working but wrote down the table stuck to the side of the PSU and replicated it here:

I don't really understand this as I know very little about electrical measurements. The statistics here seem about the same as those listed on Antec and OCZ models.

I really appreciate your help!

 

[linux_0]

I couldn't get my camera working but wrote down the table stuck to the side of the PSU and replicated it here:

I don't really understand this as I know very little about electrical measurements. The statistics here seem about the same as those listed on Antec and OCZ models.

I really appreciate your help!

Your PSU's MFG claims they can push 18A on the 12V rail which is 216W MAX.

It's hard to tell how close that is to the actual performance.




The Antec TPII 550 has 2 12V rails so it can provide more power.

http://www.newegg.com/Product/Product.asp?Item=N82E16817103931

+3.3V@32A, +5V@40A, +12V1@19A, +12V2@19A, -12V@1A, +5VSB@2A

ANTEC, OCZ, Silverstone, PC Power & Cooling PSU, Seasonic and other good manufacturers report true performance on their PSUs.

Many generic PSU manufacturers greatly exaggerate performance.

 

[Griever]

So having two rails applies to everything the PSU powers? So it supplies (2x19A=) 38A to everything in the case? Sorry to pester you with simple questions but I've wasted a lot of money on two separate PSUs (that haven't powered my machine adequately) and want to be certain before I spend any more!

 

[linux_0]

So having two rails applies to everything the PSU powers? So it supplies (2x19A=) 38A to everything in the case? Sorry to pester you with simple questions but I've wasted a lot of money on two separate PSUs (that haven't powered my machine adequately) and want to be certain before I spend any more!

http://www.antec.com/us/productDetails.php?ProdID=22550#

http://www.antec.com/specs/TPII550_spe.html


As long as your system is not drawing the maximum 32A @3.3V and 40A @5V then the Antec TPII can provide 19A to each 12V rail ( 38A total ).

+5V, +3.3V, +12V1, 12V2 maximum output 530 Watts max

That 530W is divided between the +5V rail the +3.3V rail the +12V1 rail and the +12V2 rail.


3.3V * 32A = 105.6W

5V * 40A = 200W

12V1 * 19A = 228W

12V2 * 19A = 228W

228+200+105.6 = 533.6W

However since you rarely use 32A @ 3.3V and 40A @ 5V the extra power can be used by the second 12V rail.


You don't get 38A to everything in the case.

One 12V Rail goes to the CPU. The CPU draws the power it needs any excess goes to the other rail.

The other 12V Rail goes to the 4pin molex connectors and powers your HDDs, optical drives and your PCI-E or AGP VGA card ( s ).

HDDs typically consume about 0.5A - 0.6A @ 12VDC and 0.4A - 0.5A @ 5VDC

VGA cards consume quite a bit more than the drives do.

 

[Griever]

Well, I've spent the last few hours reading reviews on the leading branded PSUs and have finally decided to go for the Hiper 580W Type-R Modular PSU [ http://www.hipergroup.com/English/products/hpu-4k580.html ].

It seems to have the best balance of features, high performance and low cost. Even though Hiper seem to be relatively small in the US they got a lot of extremely positive reviews. Hope I made the right choice... :?

Thank you ever so much for your advice and patience linux_0!

 

[linux_0]

In case you haven't read this already:

http://www.tomshardware.com/2006/02/07/5_power_supplies_get_the_full_juice_treatment/index.html

It doesn't look too bad.

:-D

 

[Griever]

Yes. However, based on United Kingdom prices the Hiper is really good value compared to rivals (I got the impression that the US version is both relatively more expensive and misses some features). I really liked the design and modular system too. Should arrive tomorrow morning...

 

[linux_0]

Yes. However, based on United Kingdom prices the Hiper is really good value compared to rivals (I got the impression that the US version is both relatively more expensive and misses some features). I really liked the design and modular system too. Should arrive tomorrow morning...

Hope it works well for ya :-D

Good luck!