David M
05-14-2005, 12:14 PM
I recently purchased this PSU to replace another PSU which was not quite adequate to power my SLI system. http://www.pcpowercooling.com/products/viewproduct.php?show=T85SSI
First thing, this PSU is a bit of an overkill for powering current SLI systems. This does not mean though that graphics cards in the future will not be able to benefit from a PSU of this size.
I have a Lian-Li 1000 case http://www.newegg.com/Product/Showimage.asp?Mode=&Type=&Image=11-112-055-08.jpg%2C11-112-055-01.jpg%2C11-112-055-09.jpg%2C11-112-055-03.jpg%2C11-112-055-04.jpg%2C11-112-055-06.jpg%2C11-112-055-07.jpg&CurImage=11-112-055-09.jpg&Description=Lian+Li+PC-V1200+Silver+Aluminum+ATX+Mid+Tower+Computer+Case+-+Retail where the PSU sits on the bottom of the case as well as the hard drives. There are two hard drive cages which hold up to 3 hard drives each. I ran into a problem installing this larger than normal PSU because the depth is about 2 inches deeper than a standard size PSU which required that I had to remove one of the hard drive bays. Having 4 hard drives meant that I had to place one of the drives above the remaining hard drive bay. Which turned out okay since there is still a fan blowing directly on all four drives. My point is that this PSU is longer than normal and it may or may not fit in your case. The height and width are the same as a standard sized PSU
The 850 is only one of four PSU's which is certified by NVIDIA for SLI use. This means NVIDIA has tested it and you don't need to worry if it is going to work on your SLI system. There is at least one PSU out there that claims it is designed for SLI but does not actually work for SLI...so be cautious.
Getting into the details, it has 4, 12 volt rails at 17 amps each and 2 PCI Express connectors each on its own separate rail. SLI graphics card manufacturers specify that each card have its own 12 volt rail. A cheaper manufacturer placed two PCI Express connectors on one rail.
The voltage tolerances are excellent at 1%. I placed a digital Fluke meter across the leads between the connector and the circuit board on both my eVGA 6800 Ultra cards both when there was a very light load and then when I was playing Halo at 1200x1600 with all the features turned up..essentially maxing out the cards. The voltage with a light load was a rock steady 12.2 volts and the voltage drop with a heavy load was a slightly fluctuating, roughly .05 volts lower reading on the volt meter. I also tested the card running 3DMark05 during the "light butterfly" scenario which really places a load on the graphics cards. I received the same results as Halo. Both tests produced results well within the stated 1% voltage tolerance. It's my opinion that power supplies that are a bit of an overkill will have much more stable voltages because your not even close to maxing out the PSU...thats my theory at least. :)
The fan noise is about the same as smaller PSU's and surprising low for a monster like this. I was expecting a louder fan. The dual fans are temperature sensitive and will run slow and quiet during light loads. When playing games that loaded up my CPU, RAM and graphics cards, the fan ran a bit faster but still was still not loud at all.
It comes with a 5 year warranty which is excellent. The manufacturer obviously has a lot of confidence in its product.
Strengths:
-Pleanty of power
-Very high quality
-Very tight tolerances and specs
Weaknesses:
-Very expensive ($469 MSRP)...Yikes!
-Deeper than normal case that may cause it not to fit.
As far as rating it, I would give it a 10 if it were not so expensive. There is nothing wrong with it other than the price and its size (which may or may not make a difference depending on your case). I give it an 8 overall.
First thing, this PSU is a bit of an overkill for powering current SLI systems. This does not mean though that graphics cards in the future will not be able to benefit from a PSU of this size.
I have a Lian-Li 1000 case http://www.newegg.com/Product/Showimage.asp?Mode=&Type=&Image=11-112-055-08.jpg%2C11-112-055-01.jpg%2C11-112-055-09.jpg%2C11-112-055-03.jpg%2C11-112-055-04.jpg%2C11-112-055-06.jpg%2C11-112-055-07.jpg&CurImage=11-112-055-09.jpg&Description=Lian+Li+PC-V1200+Silver+Aluminum+ATX+Mid+Tower+Computer+Case+-+Retail where the PSU sits on the bottom of the case as well as the hard drives. There are two hard drive cages which hold up to 3 hard drives each. I ran into a problem installing this larger than normal PSU because the depth is about 2 inches deeper than a standard size PSU which required that I had to remove one of the hard drive bays. Having 4 hard drives meant that I had to place one of the drives above the remaining hard drive bay. Which turned out okay since there is still a fan blowing directly on all four drives. My point is that this PSU is longer than normal and it may or may not fit in your case. The height and width are the same as a standard sized PSU
The 850 is only one of four PSU's which is certified by NVIDIA for SLI use. This means NVIDIA has tested it and you don't need to worry if it is going to work on your SLI system. There is at least one PSU out there that claims it is designed for SLI but does not actually work for SLI...so be cautious.
Getting into the details, it has 4, 12 volt rails at 17 amps each and 2 PCI Express connectors each on its own separate rail. SLI graphics card manufacturers specify that each card have its own 12 volt rail. A cheaper manufacturer placed two PCI Express connectors on one rail.
The voltage tolerances are excellent at 1%. I placed a digital Fluke meter across the leads between the connector and the circuit board on both my eVGA 6800 Ultra cards both when there was a very light load and then when I was playing Halo at 1200x1600 with all the features turned up..essentially maxing out the cards. The voltage with a light load was a rock steady 12.2 volts and the voltage drop with a heavy load was a slightly fluctuating, roughly .05 volts lower reading on the volt meter. I also tested the card running 3DMark05 during the "light butterfly" scenario which really places a load on the graphics cards. I received the same results as Halo. Both tests produced results well within the stated 1% voltage tolerance. It's my opinion that power supplies that are a bit of an overkill will have much more stable voltages because your not even close to maxing out the PSU...thats my theory at least. :)
The fan noise is about the same as smaller PSU's and surprising low for a monster like this. I was expecting a louder fan. The dual fans are temperature sensitive and will run slow and quiet during light loads. When playing games that loaded up my CPU, RAM and graphics cards, the fan ran a bit faster but still was still not loud at all.
It comes with a 5 year warranty which is excellent. The manufacturer obviously has a lot of confidence in its product.
Strengths:
-Pleanty of power
-Very high quality
-Very tight tolerances and specs
Weaknesses:
-Very expensive ($469 MSRP)...Yikes!
-Deeper than normal case that may cause it not to fit.
As far as rating it, I would give it a 10 if it were not so expensive. There is nothing wrong with it other than the price and its size (which may or may not make a difference depending on your case). I give it an 8 overall.