Power Supply?

  • Thread starter Thread starter Rand Al'Thor
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Rand Al'Thor

I have an AGP + standard PCI system. I don't want to go to the expense of a
completely new system so I've considered purchasing Sapphire ATI Radeon
X1950 Pro AGP graphics card. However the power supply in my current system
is only 320watts. I understand that I need at least a 450watt PSU to
effectively use this card. What confuses me is that PSUs' now state ATX2.0
or ATX2.2 and PCIe etc. I know my setup is just ATX, can anyone give me a
clue as to what I need to purchase and any recomended make?

Thanks,

Alan

SYSTEM
Intel Pentium 3.2Ghz
Sapphire ATI Radeon X850XT
1Gb Corsair DDR400 ram
 
Rand Al'Thor said:
I have an AGP + standard PCI system. I don't want to go to the expense of a
completely new system so I've considered purchasing Sapphire ATI Radeon
X1950 Pro AGP graphics card. However the power supply in my current system
is only 320watts. I understand that I need at least a 450watt PSU to
effectively use this card. What confuses me is that PSUs' now state ATX2.0
or ATX2.2 and PCIe etc. I know my setup is just ATX, can anyone give me a
clue as to what I need to purchase and any recomended make?

Thanks,

Alan

SYSTEM
Intel Pentium 3.2Ghz
Sapphire ATI Radeon X850XT
1Gb Corsair DDR400 ram
Click to expand...

You're thinking too hard. The main thing you need to know is, will the main
power connector fit your mainboard? Most power supplies are now "20 + 4",
so they will work if you have an older 20-pin power connector on your
mainboard OR if you have the 24-pin connector on your mainboard. But you
probably need a 4-pin "12V" power connector for your mainboard, as well,
which is totally unrelated to the main power connector "20 + 4". Gotta
watch out for that, as some newer power supplies are 8-pin, so that won't
work (without an adapter) if your mainboard requires a 4-pin 12V connection.

The following is really high quality at a decent price. It has the 20+4 pin
main power connector setup and 8-pin 12V power connector. It also includes
a 8-pin to 4-pin 12V power connector converter. So unless there is
something about your mainboard that you haven't told us (!), it should work
just fine for you. :) But review your mainboard manual to make sure that
this power supply has the right connectors. I'd be shocked if it didn't,
but... -Dave

http://www.newegg.com/Product/Product.asp?Item=N82E16817101111
 
Be careful with the Sapphire x1950pro, check the sapphire forums, there are
tons of posts about failing cards(both the AGP and PCI-X versions). It
appears the cooling solution for the single slot versions of the x1950pro
are not up to snuff to keep the VRMs on the board cool. You might be
enhancing the problem if you underpower the card.

Take a look at the HIS solution:
http://www.newegg.com/Product/Product.asp?Item=N82E16814161068

It uses two slots but the cooling is much better than the single slot
arrangements. The x1950pro runs HOT and needs a good cooling solution.

I am running the PCI-X version using an Antec 450W supply. I had the
shutdown failure that everyone else is having with the single slot Sapphire
card. Replaced it with the HIS PCI-X version that I linked to above and
have had zero problems with the card, it runs a good 10C cooler than the
Sapphire card(even with the fan at 50% on the HIS card vs 100% on the
Sapphire).

Do not drink the kool-aid that they're pitching on the Sapphire forums,
everyone that runs into problems with the card they're telling them to first
upgrade their power supply to something 600+W. And of course this rarely
solves the user's problem. Thus they're out the cost of a new power supply
AND whatever the RMA cost them on the original card. Sapphire really put
their heads in the sand on this one and their super moderators on the forum
are compounding user problems.

Good luck! The x1950pro is a great card if you don't run into the cooling
issues.
 
Thanks for the replies guys. Will certainly consider what you say. Forgot to
mention, my mobo is an Intel D865GLC, must be at least 18 months old

Alan
 
Rand said:
I have an AGP + standard PCI system. I don't want to go to the expense of a
completely new system so I've considered purchasing Sapphire ATI Radeon
X1950 Pro AGP graphics card. However the power supply in my current system
is only 320watts. I understand that I need at least a 450watt PSU to
effectively use this card. What confuses me is that PSUs' now state ATX2.0
or ATX2.2 and PCIe etc. I know my setup is just ATX, can anyone give me a
clue as to what I need to purchase and any recomended make?

Thanks,

Alan

SYSTEM
Intel Pentium 3.2Ghz
Sapphire ATI Radeon X850XT
1Gb Corsair DDR400 ram
Click to expand...

The X850XT is 68.6 watts.
http://www.xbitlabs.com/articles/video/display/gpu-consumption2006_6.html

This X1950Pro is 65.7 watts. This could be the PCI Express version, in which
case the AGP version has the Railto bridge on it. Maybe allocate an extra
few watts for that. AFAIK, the AGP and the PCI Express are clocked the same.
But the AGP version gets a bit less performance, due to AGP. Which means
the power will actually be less than the 65.7W (do less work, draw less
power).

http://www.xbitlabs.com/articles/video/display/x1950pro-gf7900gs_6.html

Which means, in terms of the "power class" of the two cards, they are
about the same. The reason the power will drop a bit on new cards,
is due to the use of finer geometry silicon. That is compensated by
stuffing more circuitry on the chip.

The rails that the power is drawn from, can vary from design to design.
The X850XT uses a Molex 1x4, meaning the card has access to +5V and
+12V, and could use some of both. The HIS X1950Pro AGP has a PCI Express
2x3, meaning 12V is used. A Diamond card uses two Molex 1x4, which is
a bit strange, same as Sapphire. In fact, it doesn't look like the
manufacturers are all using the same reference design.

But at the current time, I don't see a reason to panic.

To work out some numbers, it would help to have a full hardware inventory,
including the SLxxx number on the processor box if you've got it. Even
knowing whether the processor is Northwood or Prescott would help. Also,
the ratings on the side of the supply would help. You'll see something
like this on the label.

+3.3V@32A, +5V@32A, +12V@26A, -5V@1A, -12V@1A, [email protected]
3.3V & 5V to 185W
total power 350W

If you just want to go out and buy another supply, that isn't a problem.
The ATX 2.0+ supplies are dual rail, and may offer a 20+4 connector. The
20+4 splits into two pieces, if you just want a 20 pin connector. The
processor is tied to 12V2 rail. The rest of the system runs off 12V1.
(The older supplies just had "12V" and a single supply rail.)

As an example of processor power, a Prescott 3.2E draws 89W. And
my usual assumption is 90% Vcore converter efficiency.

http://processorfinder.intel.com/details.aspx?sSpec=SL7E5

89W/12V * (1/0.90) = 8.24A for 12V2.

The 12V1 would be 2.5A for a CD, a HDD, some fans, plus allow
about 70W from 12V1 for the video card with the 2x3 PCI Express
power connector. 70W/12V = approx 6A. So 8.5A on 12V1 would be
the bare minimum, to run the new card.

This is an example of a 400W ATX 2.0+ supply.
+3.3V@30A, +5V@30A, +12V1@18A, +12V2@18A, [email protected], +5VSB@2A
12V1 and 12V2 to 345W.
http://www.newegg.com/Product/Product.asp?Item=N82E16817104952

By calculation, (8.24A + 8.5A) * 12V = 201W and fits within the
345W limit on both 12V rails. The 3.3V and 5V have a max power
of 150W total, and 50W is a ballpark estimate for the average
setup. Which means, when gaming, I'm estimating ~250W of
power usage at the output of the supply.

Even this supply has the specs to meet the application, and has
a total rating of 380W. But the trick is to read the reviews,
to help separate the good ones from the bad ones. A supply has
to have a clean review record, and meet the specs, to be worth
taking a shot at. Using the reviews is about the only way, to
find the ones with honest labeling.

http://www.newegg.com/Product/CustratingReview.asp?item=N82E16817182047

Paul
 
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