low$ cad/3d gfx cards vs PS & old mobo?

Xbitlabs has been measuring power, in their video card reviews, on and off since those two articles above. To find power, go to this page:

Enter something like this in the top line

7600 GS power

Note that they don't tend to abbreviate the part number to 7600GS, so it is a good idea to put a space between the two parts of the name.

Set "Search Using" to "All Words".

You may have to look through a few pages, but eventually you'll find a table with power numbers.

Another good pair of words to use for a search:

Contemporary power

They like to use "contemporary" when reviewing the current crop of cards. This article is from July 2006.

There should not be a big difference in power draw if using two monitors. If the card is in 3D mode, it should already be drawing the power stated in the Xbitlabs measurement. Running another DAC or running a TMDS interface won't make that much difference. Running two monitors is more demanding of the video card memory bandwidth, and so selecting the cheapest card might not help in that regard.

What will make a difference, is trying to run two monitors with a Duron 800. The processor could well be the rate limiting thing.

To work through a reasonably modern example, I picked this card:

ASUS N7600GS SILENT/HTD/256M GeForce 7600GS 256MB 128-bit GDDR2 AGP 4X/8X $87

The card has 256MB of onboard RAM. The interface to that RAM is 128 bits wide, whereas a lot of low end cards only use 64 bits. The really expensive cards have 256 bits or more in width. Width helps with GPU to video memory bandwidth.

That card memory is probably "true memory". The low end cards sometimes use Turbocache or Hypermemory, and you have to read more than one version of advertising copy, to see an admission that the card uses something like that. You don't have a lot of system RAM, so sharing some for video is not going to work well. It is possible, if the driver detects a small amount of system memory, that the "cache" effect would be disabled, and the card might work a bit speedier.

The above Asus example card, has an aluminum heatsink. I would estimate the power of the card at around 35W or so. (Allowing a couple watts for the HSI bridge chip on the back of the card.)

The card has a disk drive connector on the end of it.

I have a couple fanless video cards here, and what I do is mount an

80mm case fan next to the video card. That keeps the card stable in 3D mode. Both my cards are fine in 2D (desktop) mode, but one of them overheats in 3D mode. Using a fan fixes that for me. Since it is a case fan, if the case fan wears out, it is easy to replace. Not so with some of the cheap fans used on video cards - they can be hard to find a replacement for, and sometimes you have to use an aftermarket heatsink and fan to do the job.

On the faceplate side, there are three connectors. Video at the top, VGA in the middle and DVI-I on the bottom. Some combination of two of three connectors can be used at a time.

The DVI-I connector has two sets of signals on it. There are digital signals (TMDS) suitable for driving an LCD. Note that a lot of cheap LCD monitors only have a digital connection on them, and the fact that the 7600GS AGP card shown above has a VGA connector, means you could potentially have a problem if you switched to two cheap LCD monitors in the future.

The second set of signals on the connector, are suitable for driving a VGA monitor. They are analog signals. The signals on the "cross" at one end of the DVI-I connector, are 75 ohm RGB for analog VGA.

That video card also comes with a "DVI to VGA dongle". What the dongle does, is extracts the VGA signals and puts them on the familiar 15 pin connector. Using that dongle, you can drive two VGA CRTs for example.

Some cheap video cards have DVI-I connectors, but no dongle is included in the package. Having to buy it separately, adds to the total price. You only have to buy a dongle, to convert a DVI-I to an analog VGA for an older monitor like a CRT monitor.

So there is room to cut corners on video cards, but you may not end up getting all the features you were looking for.

More info here. Non-quadro cards are listed as fine, as long as the video card has sufficient memory for the number of open windows. (click "tested" button.)

Paul

26 Aug 2007,Paul in news:fatm30$ukb$ snipped-for-privacy@aioe.org:

"wow wow wow". This is exactly why i need to ask questions. thank you. I was nowhere near discovering some of the aspects you outline below. And of other aspects, i'd only noticed the phrases, but not (yet?) realized their significance to me. Also, (not buttering you up, just noticing..) the way you typed this up, you appear super familar.

Summary: my PS almost certainly limits me to old cards. My PS is strong on +5v and weak on +12v. My revised selection criteria: low-cost, reliable (new/warranteed/RMA-able or fanless used). Very secondary criteria: bandwidth, vram, dual-crt.

I'd like to know whether I'm stuck choosing from used 16mb-era gfx cards (eg, tnt2. And of course I'd research these myself). AFAIK any fan card old enough to use +

5v, will have worn out fans. Maybe the low-end agp cards (such as fx-5500oc, see below) draw low enough power for my +12v line to supply?

(data from

My PS looks fine for summed wattages: Sparkle's summed (+5v & +12v) ratings are: 175W for my ATX-300GT (site's values match my label's) 120W for ATX-300PA and ATX-300PN (two newer 300w models with +12v1

+12v2 lines) Sparkle total of all "+" lines are: 280W for all three models.

i found posts which summed +12v demand (including a recent post by you (Paul 'nospam needed') :-) )

mobo + 1hd + usb hd + fd + 2cd + gfx card = amps, +12v ??? + 0.5 + 0.2 + 5 + 2 + ???gfx = ???Amps [my PS label rsays +12v==13A]

Details: cpu. I strongly suspect AZ-11 mobo feeds Duron 800Mhz either 3.3v or 5v. 800Mhz maxes 35.4w at 1.6-1.7v. I can't find or further decipher AMD spec info. usb hd. i guessed at USB signal watts. Probably negligible. Might be 3.3v or

5v. The external usb hd has own PS in power cord. I have no usb mouse, keyboard, or "usb hub". floppy. Generic 5 watts from googling

Zero amp stuff: nic. Dlink pdf on cd says 0.8w(240mA)max 3.3v. ram. Runs off 3.3v?

0fans. No case fans because it's a 110v a/c deskfan strapped to the open side of case. Seems very good flow.

??? amps: gfx card. Depends on card, but assuming the fx5500oc agp, i will probably phone BFG, asking for link to published specs (with power vs volt lines). fx5500 lacks hd power plug, so should need less than agp (2.0 or 3.0) spec's max? mobo. can't find info yet. az-11 manual warns only about min 200W PS, supplying

20A, +5v and 10mA, +5Vsb. (Maybe acronyms in the manual would imply likely approximate amps?)

i thought comparing amps (+12v?) of this Rage iic gfx card might be useful, but can't find that.

I googled for VIA KT133 conflicts. So far, I've found no explosive looking info.

the power question is probably all that's puzzling me...

___________ but for anyone interested (google archaeologists) the following is my ~2nd sweep thru the research process

[snip] sampling: implies that bang-for-buck, 9500 pro does well against 9600 xt. But this is a speed benchmark. And not only do we minority 'workstation' users have to filter thru gaming-oriented info, but various cad/modeling software probably need differing benchmarks (all of which are obscure?)

Bad for me: xbitlabs never ran an fx-5500. Though possibly they ran another NV34 based card.

ok. Data bits is larger when dual-display, while data watts is negligibly different.

i haven't googled this yet, but i wonder: is CRT power demand *of the data* roughly a factor of total pixels? or of display area? (or neither?)

bit width Radeon 9500 Pro 128 Radeon 9600 XT 128 or 256 (later implies both are native-agp)

en.wikipedia.org/wiki/GeForce_FX_Series#GeForce_FX_models FX 5500 NV34 64 or 128 bit native-agp

BFG site's info is skimpy. Can't find bit-width, but bfg fx5500oc is probably

64-bit

yes [snip]

[snip clarification on output & power connectors]

those used ati's are fully featured. but lack of HD plugin for fx5500oc agp suggests it needs less power. but the fx5500 lacks dvi out. According to those wikipedia pages, all agp have "true" vram/memory. Implies that it doesn't matter whether cards may be native pci-e , because running thru agp- spec slot means they can't cache.

[perhaps appropriate disclaimer: i didn't intend to mislead anyone to thinking i expect to be using solidworks. this ng was most common in results from googling.]

I chose "ATI"," winxp". SW chart shows: ATI 9500 Pro passes w/limitations (see popup). Note that 9600 pro is in same group, so possibly SW never tested 9600xt, yet it would be similar. For "ATI", clicking "show all" button gives the same chart of cards.

SW2008 is likely not yet tested.

______________ boredom alert. leftover thoughts: NV34, last of native-agp? Anisotropic Filtering apparently slows the FX cards, but this may be an example of a tradeoff that benefits modelers.

bfg fx5500oc is probably 64-bit:

2004 "as verified by a phone call to BFG....well hell, they don't even know... all the engineers had left for the day." "it was 64-bit One of the main reasons I took it back to Best Buy."

lack of 'turbocache' is actually performance disadvantage, but *should* force advertisers to list vram correctly. OTOH, why not also 'turbocache' the fastest cards?

gfg4 are last of +5v powered cards (don't know which ati are last +5v)