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how many phases in a graphics card?

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caldran

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how to determine how many phase power a graphics card has.......i ve seen many using different design ....one way is to find out the number of coils....each coil constitute a single phase.....but the reference design has smaller coil....
so how to find it out.....
 
Look up the manufacturer specifications.
 
^^ what he said, it varies from card to card, to manu to manu.. some, like gigabyte have like 6 phase power and really good stuff for their cards, whereas something as foxconn will be reference design and bare minimum in features and quality.
 
ya ....this thread it to find out how to identify it...ie before buying.....like the xfx in 8800gs and the new cheap evga i think has less power phase to reduce cost....but i could nt confirm it....
i ve read people complaining about strange coil noise...is it related to this...
 
gigabyte doesn't have 6 phase power on video cards.

count the smd inductors. there are a couple kinds they look like this.

cap3zm3.png


4 on a card = 3+1 phase
3 on a card = 2+1 phase

- Christine
 
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My palit has those solid black ones are those good?
 
they probably vary in quality. the gray ones on the left are reference nvidia and ati. the last one with no cover are used on uncommon cards by vendors like chaintech and asus.

- Christine
 
calvary1980 said:
they probably vary in quality. the gray ones on the left are reference nvidia and ati.

- Christine
Click to expand...

what are the ones all the way far right? i have 3 of those things on my mobo.. im guessing 2 phase power?
 
I don't think any motherboard is 2 phase. lol they use like 6,8,12,16 phase.

- Christine
 
more then 3 means good.....
can it be found out using mosfets.....or capacitors......
and how many does this card have.....5
 

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it's probably 3 phase. I asked Largon to check this thread out he should provide better answers. if he doesn't im going to volt mod his balls.

- Christine
 
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The amount of inductors (aka. coil/choke) is usually a good way to determine the amount of phases. On video cards it's pretty much the rule. But it doesn't always stand... ;)
"Phase" is essentially a chain of mosfets that gradually converts 12V source voltage into core voltage that chips like GPUs and CPUs operate on. Mosfets and their configuration define individual phases.
caldran said:
and how many does this card have.....5
Click to expand...
That card has, infact, two vGPU phases + 1 vMEM + 1 vDDQ ("the other memory voltage").

So this card is a good exception of the "inductor rule". :)
On a quick glance one would say there's 4 vGPU phases as there's 4 vGPU coils... But if you look closely you'll see that each of the vGPU mosfets has a pair that is soldered on pads directly connected to each other. Both phases are built out of 4 mosfets which are set up in two pairs. Each mosfet shares the load with another mosfet by it's side.

2_1_1_phaser.jpg


1: vGPU coil #1, two parallel coils
2: vGPU phase #1, four mosfets (2 high + 2 low side)
3: vGPU coil #2, two parallel coils
4: vGPU phase #2, four mosfets (2 high + 2 low side)
5: vMEM coil
6: vMEM phase, 2 mosfets (1 high + 1 low side)
7: vDDQ coil
8: vDDQ phase, 2 mosfets (1 high + 1 low side)
 
sSig_thankyou.gif


- Christine
 
very informative Largon, so how many vGpu phases does a 9800GTX have? especially as compared to 8800GTS/GT (G92)

i am to understand that it is;

9800GTX = 4 x vGpu Phase
8800GTS = 3 x vGpu Phase
8800GT = 2 x vGpu Phase ?
 
wolf said:
9800GTX = 4 x vGpu Phase
8800GTS = 3 x vGpu Phase
8800GT = 2 x vGpu Phase ?
Click to expand...
That is correct.
9800GTX also has dedicated phases for both vMEM and vDDQ, whereas 8800GT & GTS has a unified vMEM/vDDQ phase.
 
i think that alone justifies the premium of a 9800GTX over an 8800GTS or GT.

hello overclocking :D
 
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