Parhelia 4 Pipelines?

[Unicron]

Sorry, someone might have pointed this out before but over at digit-life (digit-life.com) they keep referring that maybe the parhelias (4) Texture Units/Pipelines are only operating at either 1x4 or 2x4 why is this? dodgy drivers or broken chip?

(Quote from digit-life)

"So, in the DX 8.1 SDK tests the Matrox Parhelia 128 MBytes has a very low position. We didn't expect that because it has 4 vertex shaders but enables just one. It may be caused by the imperfect drivers or errors in the chip. Operation with the pixel shaders of the Parhelia is superb. Though it's still slower than the Ti 4600"

You have to remember this card has twice as many pipelines (4) than any card on the market and just because its running at 220mhz it should still give any gf4ti a run for its money!

Are matrox trying to fix this problem in the drivers at the moment?, it just annoys me that I have parted money for this card and it doesnt seem to be running at its full potential...

Just wanted a few owners thoughts.

Thanks

Peace out.....

[K6-III]

I think its waiting for DX9...

[Unicron]

What? do you think games will have to specifically written for dx9 or will unlock all rendering pipelines when dx9 is just installed and running?

[K6-III]

Not sure, but I think it has something to do with it....

[TdB]

AFAIK, it is operating at 4X4, (four tmus on each of the four pipelines), and all four tmus on each pipeline does gets utilized in games, even in normal dualtextured games.

This is because the 2 extra tmus is used for making additional texturesamples when trilinear filtering is enabled.

just try to benchmark some games in high resolutions with trilinear/bilinear filtering, and you will notice that trilinear filtering is practically free.

example:
quake3 at 1152*864*32 everything max with trilinear: 102 fps

quake3 at 1152*864*32 everything max with bilinear: 106 fps


for some reason this only aplies in high resolutions, I am a bit puzzled about that, in low-res the difference is much bigger(but who cares about low-res ).

[Unicron]

Have you actually read the review over at digit-life.com though!
I still think that the Parhelia rendering pipelines are being disabled in most games at the moment.... either 1 or 2 are operational.

[TdB]

yes, i glimpsed through the review, a while ago, but I think they are wrong.
My personal guess is that the parhelia is VERY cpu dependent, and that it will scale linearly with faster cpus, untill it archives the speed one would expect from the parhelia, this might not happen in the near future though.

exactly why do you think some of the pipelines are disabled? can you come up with a way to test this?

the reason I think they are all working is because the fillrate tests in3dmark2001se would be far too high otherwise, there is no way a 2pipe x 4tmu or even a 3pipe x 4tmu could get that fillrate, atleast not with the clcokspeed the parhelia has.

[Unicron]

Do you think games will need dx9 features for the Parhelia to really excel or just a few more driver updates?

I hope Matrox can squeeze alot of performance e.g 20/25% more from drivers Nvidia and ATi have already done it.....

Thanks

[K6-III]

Current driver releases will focus on compatibility.....optimization will come later...

BTW, ATI didn't start from scratch....

[TdB]

hmm!
I must admit I am already impressed with the parhelia, I think all that is needed, is that gamedevs begins to take advantage of dx8.

my guess is that the parhelias strenght isn´t found in a special corner in its feature set, but that its strenghts is that it can use ALL its features at once, without dropping the framerate.
The reef demo illustrates this convincingly, it has high poly counts AND excessive pixleshader usage AND extremely complex vertexshaders-programs running at the same time.
techdemos for other cards usually illustrates one feature at a time(AFAIK).

what we have seen in games untill now has been very limited use of dx8 features("lets pixelshade the water, it only fills 20% of the scene, and if fills more, then we make damn sure the poly count is low in the particular scene").
most dx8 games were designed with the geforce3 in mind, so they usually try not to bog the game down, by using all the dx8 features all at once. when developer begins to do just that, THEN we will see what the parhelia is all about. I don´t think that kind of dx8 games will appear before dx10 arrives, though.

[xortam]

Have we seen anyone ship SW that exploits the P's DAT feature? I would have expected this feature to have really promoted the P by now.

[Helevitia]

I used a benchmark on my 9700 yesterday that exploited that feature I think. Let me see if I can find it...

[Helevitia]

Here it is

http://users.belgacom.net/xvox/

[Helevitia]

Originally posted by xortam
Have we seen anyone ship SW that exploits the P's DAT feature? I would have expected this feature to have really promoted the P by now.

Also, I think the feature isn't being exploited because DX9 isnt out yet.

Dave

[GNEP]

XVox DAT is done in software as far as I can tell.

gnep