All 7900 owners please check something..!

[NightCrawler™]

The mystery seems solved... On a Dutch forum I'm a member of a news article was posted about the new Sparkle Calibre 790+

Immediately I noticed something different.. they've changed the capacitors on the back of the card...

The Sparkle:


The XFX 550M Extreme:


If you look at the capacitors you'll see the mint marked ones are replaced by purple marked caps... Thus it's easy to assume Sparkle didn't use the reference design and changed the caps to different ones... why.. probably cause the caps used on the reference model are at fault and cause all of the issues 7900 owners have...
So are we seeing another cap issue with the 7900 cards as we did with the 6800 series.. well it looks that way doesn't it.

So people who got their 7900 RMA'ed should look for different purple marked caps on their 7900

[The_NamelessOne]

...my new 7900gt has purple marked caps...probably this is the difference between old and new pcb revisions we were talking about i'm sure sparkle card is using reference pcb,looking at the picture it is identical to my evga reference... but it may be the new revision..

[NightCrawler™]

It's the caps they replaced... after some more searching it's limited to only two of them, the ones placed at the side of the PCIe connector near the voltage regulator...




Those two mint green caps are replaced by purple marked ones...

[naelq]

interesting!!
so, you say to look for 7900GT's with purple colored top, near the regulator's area?


NaeLQ

[NightCrawler™]

That seems to be the key component... It's the only thing which has changed compared to all the other GT's as shown in the images.
I don't know exactly what those caps are for but if they regulate the current, and fail, it would explain the artifacting..

[The_NamelessOne]

i'm not sure...i think the major problem are the ram vr on the back of the card...probably they break when overheating and supply a higher or lower voltage to vram...that exlpains why in some cases underclocking ddr under default speed solved artifacts problems....

[DesertShooter]

do you mean these?:

[NightCrawler™]

Yes...

[Zeus]

The caps on the back of the card?
You prolly meant the front, right?

Mine also has blue/mint marked caps so it might hold some truth, but how do we know the purple marked caps solved the problems?

[itznfb]

start overclocking the hell out of them and if they start failing, then we know they didn't fix it

[NightCrawler™]

The caps on the back of the card?
You prolly meant the front, right?

Mine also has blue/mint marked caps so it might hold some truth, but how do we know the purple marked caps solved the problems?

It depends on which way you look at the card I suppose... LOL

My guess is pretty simple.. This Sparkle card is brand new.. designed and released after the entire commotion about the 7900 series and after companies acknowledged the problem. It would seem illogical to release a brand new card which still has the same flaws every other card has...

[Zeus]

In a way..yes. It might make sense as the caps are on the direct opposite of the small ic's for vreg that get so darn hot.

Maybe these don't get as hot as they used to get now with the new caps?

Please forgive my skeptical attitude towards the manufactures of these 7900GT cards.
I thinks these cards should have been tested more thoroughly prior to release in the first place.

I thought evga came up with a different solution?
Their new cards have some extra components on the back and had some more Vgpu in 3d, i assume that didn't solve the prob?

[The_NamelessOne]

i agree with you....those vgas should have been tested more before being released on the market

[NightCrawler™]

I'm willing to take it one step further.. they based the 7900 series on the 7800 models.. just look at the image below.. especially the area where the caps were changed...



You can also clearly see they used purple caps for that area... My guess is they tried something with other caps for god knows what reason and it clearly didn't work... hence them going back to the purple marked caps..

[itznfb]

so the blue caps on the back are good?
or the purple caps are good?

[NightCrawler™]

The purple ones are the good ones....

Here's another comparisson.... *warning the images are huge!!*

7900GT:
http://www.club-3d.com/distri/images.../CGNX-G796.jpg

7800GT:
http://www.club-3d.com/distri/images...NX-G786VDD.jpg

The value of the caps seems to be the same 180/16 but there's another difference and I can't tell it from the numbers...

[DesertShooter]

I just bought a new XFX 7900GT. But the caps are still green.

[NightCrawler™]

I hope I'm wrong about this capacitator thing else you're stuck with a card which is going to get screwed up sooner or later....

[Zeus]

So what you're trying to say is that the vreg part for the mem is identical on both 7800GT and 7900GT except for the caps, right?

But what mem does the 7800GT carry and what voltage did it require?
What about timings? Tighter timings require more voltage.
Does the 7800GT carry Samsung mem?

Perhaps the mem on the 7900GT is taking up more current?
The mem chips get hot as hell during 06 deep freeze test, to me this is a sign that a lot of current is taken.

Anyone ever measured Vmem droop under heavy 3d violence?

[NightCrawler™]

If I look at the layout I'm tempted to say yes... If it is the same I can understand why they reverted the caps back to those purple ones as no 7800GT suffers from instant artifacts unless you're OC'ing with not enough juice...

I've spent hours searching for images and so far all 7900GT's have mint green caps there and all 7800GT's purple...
On the website of Sparkle you can see a regular 7900GT.. with purple caps..

[itznfb]

xfx 7900GT extreme is shown with purple and blue caps. these are bad?

EDIT: actually all the cards i've looked at have purple and blue caps. i haven't seen any with green.

[NightCrawler™]

Mint green / blue.. depends on the flash used I suppose...

The only caps concerned are the ones outlined here:


Those are purple now on the Sparkle model

[itznfb]

ok, i got it.

but the sparkle model is the only one with purple caps?

[NightCrawler™]

That is correct...

[naelq]

any new?

next week i'll check some 7900GT's we have in stock, & see whether they have the mint/blue colored Caps or the purple ones...