Was the X1800XT designed to have 16 pipelines or 32?

SickBeast

Lifer
Jul 21, 2000
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I'm just curious; it actually seems like ATI designed these cards to only have 16 pipelines, surprisingly enough. Any info?
 

stelleg151

Senior member
Sep 2, 2004
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I doubt it sickbeast. R580 will supposedly have 48 though, so dont get your hopes down. Think of the possibility of unlocking 24 pipes.... mmmmm.
 

tuteja1986

Diamond Member
Jun 1, 2005
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Originally posted by: SickBeast
I'm just curious; it actually seems like ATI designed these cards to only have 16 pipelines, surprisingly enough. Any info?

They had plans for 32 but didn't work out and it got changed and things got taken out and then they went supper extreme Pipeline *(
 

SickBeast

Lifer
Jul 21, 2000
14,377
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Originally posted by: tuteja1986
Originally posted by: SickBeast
I'm just curious; it actually seems like ATI designed these cards to only have 16 pipelines, surprisingly enough. Any info?

They had plans for 32 but didn't work out and it got changed and things got taken out and then they went supper extreme Pipeline *(

So you're telling me that all these new GPUs do not have any disabled pipelines by default?
 

SickBeast

Lifer
Jul 21, 2000
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Originally posted by: stelleg151
I doubt it sickbeast. R580 will supposedly have 48 though, so dont get your hopes down. Think of the possibility of unlocking 24 pipes.... mmmmm.

:D
 

crazydingo

Golden Member
May 15, 2005
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Originally posted by: tuteja1986
Originally posted by: SickBeast
I'm just curious; it actually seems like ATI designed these cards to only have 16 pipelines, surprisingly enough. Any info?

They had plans for 32 but didn't work out and it got changed and things got taken out and then they went supper extreme Pipeline *(
You are being a mouth peice of Inquirer. :p

R520 was designed as 16 pipeline gpu from the get-go. ;)
 

Cookie Monster

Diamond Member
May 7, 2005
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IT was designed as a 32pipe line beast. Yield wasnt good enough, and power leakages, so it took a step back to 24pipe.

That is why sites like hkepc presumed the R520 would be 24 pipe, because there was engineering samples off it, and indicated to many it was going to be a 24 pipe card.

But still yields were bad, so 16 pipe, and this removed the yield problems, plus later on fixed the power leakage.

R580 is going to a 16pipe card with 3 ROPS per pipe, making it 48 fragment pipe card.
 

crazydingo

Golden Member
May 15, 2005
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Originally posted by: Cookie Monster
IT was designed as a 32pipe line beast. Yield wasnt good enough, and power leakages, so it took a step back to 24pipe.

That is why sites like hkepc presumed the R520 would be 24 pipe, because there was engineering samples off it, and indicated to many it was going to be a 24 pipe card.

But still yields were bad, so 16 pipe, and this removed the yield problems, plus later on fixed the power leakage.

R580 is going to a 16pipe card with 3 ROPS per pipe, making it 48 fragment pipe card.
If such was the case, imagine the die space wasted. 32 pipe theory only existed in the cabinets of the rumor mills. :D
 

Keysplayr

Elite Member
Jan 16, 2003
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Originally posted by: crazydingo
Originally posted by: Cookie Monster
IT was designed as a 32pipe line beast. Yield wasnt good enough, and power leakages, so it took a step back to 24pipe.

That is why sites like hkepc presumed the R520 would be 24 pipe, because there was engineering samples off it, and indicated to many it was going to be a 24 pipe card.

But still yields were bad, so 16 pipe, and this removed the yield problems, plus later on fixed the power leakage.

R580 is going to a 16pipe card with 3 ROPS per pipe, making it 48 fragment pipe card.
If such was the case, imagine the die space wasted. 32 pipe theory only existed in the cabinets of the rumor mills. :D

True. But also keep in mind that these rumors had a LONG time to gain momentum with all the waiting. So, it's going to take a while to go away. The X1800 series are 16 pipe cards without any disabled pipelines. (Repeating just for emphasis ;) )

 

Acanthus

Lifer
Aug 28, 2001
19,915
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ostif.org
Originally posted by: stelleg151
I doubt it sickbeast. R580 will supposedly have 48 though, so dont get your hopes down. Think of the possibility of unlocking 24 pipes.... mmmmm.

That is not correct. R580 is the refresh GPU. R600 is next gen unified GPU that will feature 48+ unified piplines (like G80).
 

Steelski

Senior member
Feb 16, 2005
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Originally posted by: Cookie Monster
IT was designed as a 32pipe line beast. Yield wasnt good enough, and power leakages, so it took a step back to 24pipe.

That is why sites like hkepc presumed the R520 would be 24 pipe, because there was engineering samples off it, and indicated to many it was going to be a 24 pipe card.

But still yields were bad, so 16 pipe, and this removed the yield problems, plus later on fixed the power leakage.

R580 is going to a 16pipe card with 3 ROPS per pipe, making it 48 fragment pipe card.

Sorry but this seems a bit BS as the R520s that did not clock high enough are in the X1800XL cards. They are also 16piped unless anyone has any other info. I cant remember where I read this but it seems plausable that ATI was having misfires with the R520s and we will see those in the XL's the ones that were taped out after the problems are the ones in the XT's and in the future XL's.
I would really like to see a 12 piped version of the R520 and then mod the heck out of it. there is a massive market in that as the GTO2 seems to be showing.
I had a 9500 128mb non pro which was cheap but was modable to the lovely 9700 speks...........
aaaaaaaaaaaaaaaah

I would like to see an engeneering sample of a 24piped R520 as that would most def beat you, me, his mom and her neigbourhood with a 24" stick.
 

Creig

Diamond Member
Oct 9, 1999
5,170
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I don't plan on saying "Yea" or "Nay" to the theory of hidden pipelines until the cards have been in the hands of some unlocking gurus for a couple of months. I keep thinking about transistor counts.

16 pipelines - 6800 U - 222 million transistors
16 pipelines - X800XT - 160 million transistors


And both cards are equipped with 16 pixel pipelines. Now today we have:


24 pipelines - 7800GTX - 304 million transistors
16 pipelines - X1800XT - 321 million transistors


The transistor count only went up 37% when going from a 16 pipeline 6800U to the 24 pipeline 7800 GTX. And yet somehow the X1800XT transistor count literally shot through the roof from the 160 million X800XT to the 321 million X1800XT. That's a 100% increase in transistors over the X800XT and yet they're both supposedly 16 pipeline cards.

Yes, the X1800XT has many new features such as full-speed 32-bit precision, SM3.0, "Ring Bus" memory architecture, and a new shader engine. But I don't believe those features can fully account for 161 million transistors.
 

Munky

Diamond Member
Feb 5, 2005
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For all the confusion regarding the r580: it's planned to have 16 ROP's with 3 pixel shaders per ROP, not the other way around. It gives it a total or 48 pixel shaders, and 16 ROP's. This is based on the leaked Ati slides, discovered months ago at B3D, that also described the r520, rv530, and the rv515, and all of which turned out true so far. Based on those slides, the r520 was designed as a 16 pixel shader card.

The whole notion of pipes no longer applies to the new Ati cards, because the pixel shaders and the texture units work independently, and thus are not tied to any singular "pipes".
 

Genx87

Lifer
Apr 8, 2002
41,091
513
126
Originally posted by: Acanthus
Originally posted by: stelleg151
I doubt it sickbeast. R580 will supposedly have 48 though, so dont get your hopes down. Think of the possibility of unlocking 24 pipes.... mmmmm.

That is not correct. R580 is the refresh GPU. R600 is next gen unified GPU that will feature 48+ unified piplines (like G80).

Somehow people on Beyond3d have convinced themselves a GPU within the same generation will come out with 3 times the pipelines.

Makes a lot of sense if you ask me ;)
 

Genx87

Lifer
Apr 8, 2002
41,091
513
126
Originally posted by: Creig
I don't plan on saying "Yea" or "Nay" to the theory of hidden pipelines until the cards have been in the hands of some unlocking gurus for a couple of months. I keep thinking about transistor counts.

16 pipelines - 6800 U - 222 million transistors
16 pipelines - X800XT - 160 million transistors


And both cards are equipped with 16 pixel pipelines. Now today we have:


24 pipelines - 7800GTX - 304 million transistors
16 pipelines - X1800XT - 321 million transistors


The transistor count only went up 37% when going from a 16 pipeline 6800U to the 24 pipeline 7800 GTX. And yet somehow the X1800XT transistor count literally shot through the roof from the 160 million X800XT to the 321 million X1800XT. That's a 100% increase in transistors over the X800XT and yet they're both supposedly 16 pipeline cards.

Yes, the X1800XT has many new features such as full-speed 32-bit precision, SM3.0, "Ring Bus" memory architecture, and a new shader engine. But I don't believe those features can fully account for 161 million transistors.

ATI has said doing FP32 will cost 50% more transistors. Without even blinking they knocked it upto ~240 million. Now the other 80 or so million transistors can be a disabled quad, maybe the new memory controller, maybe some of the AA and AF enhancements, maybe the new dispatcher?

I will say at best it probably has 24 pipes and I bet this is what you will see with the R580.
 

Soccerman06

Diamond Member
Jul 29, 2004
5,830
5
81
I remember reading on the forums a pritty good theory.

The X1800XL/XT were always ment to have the 16 pipes, but just be faster/more efficient. The R580, which started to be made around the same time as the R520, was going to be a 24 pipe card with the same speeds or close to R520. But something went wrong when trying to produce the R520 so it comes out later in the year. The X1600 cards were suppose to be a weaker R580 (cant really say disabled pipes or lower clock as we dong know anything about the GPU yet). Because we have no definate proof of what the R580 is, this is only a theory, but it could be possible.

Sorry didnt really come out right, when I read the guys thread, he put it in much better terms than I did, but whatever you get the point.

Anyways, I would rather have a X1800 with agp before I see the R580 simply because my gaming rig is still agp. But yes, there seems to be an excess of a few million trasistors on the R520 which leads me to believe that there is something more than what meets the eye (or it could just be that super AA thing).

Anyone actually read AT review on the X1800XT/XL and find somethings peculiar, like how there is no XT benchies for DoD. I know AT said that ATI had a "bug" in their manufacturing process that limited the speed of the XT and would not allow the card to reach its proper speed, so ATI labeled all the cards as XLs. What Im wondering is, does this meen the first few batches of XLs barely OC, because if ATI couldnt get them to run at proper speeds meens they probably wont OC well. Maybe when the "bug" is fixed we'll see higher clocks and OC. Of course Im just assuming that would be a problem.
 

Munky

Diamond Member
Feb 5, 2005
9,372
0
76
Originally posted by: Genx87
Originally posted by: Creig
I don't plan on saying "Yea" or "Nay" to the theory of hidden pipelines until the cards have been in the hands of some unlocking gurus for a couple of months. I keep thinking about transistor counts.

16 pipelines - 6800 U - 222 million transistors
16 pipelines - X800XT - 160 million transistors


And both cards are equipped with 16 pixel pipelines. Now today we have:


24 pipelines - 7800GTX - 304 million transistors
16 pipelines - X1800XT - 321 million transistors


The transistor count only went up 37% when going from a 16 pipeline 6800U to the 24 pipeline 7800 GTX. And yet somehow the X1800XT transistor count literally shot through the roof from the 160 million X800XT to the 321 million X1800XT. That's a 100% increase in transistors over the X800XT and yet they're both supposedly 16 pipeline cards.

Yes, the X1800XT has many new features such as full-speed 32-bit precision, SM3.0, "Ring Bus" memory architecture, and a new shader engine. But I don't believe those features can fully account for 161 million transistors.

I will say at best it probably has 24 pipes and I bet this is what you will see with the R580.

How do you figure that? Ati has already shown that they dont rely on increasing the number of "pipes" as the primary way of boosting performance. What they do instead is design the card with a 3:1 ratio of pixel shaders to TMU's, since modern games rely heavily on pixel shaders. This is what they have done on the rv530. The new architecture is flexible enough to let them increase the number of units that matter (pixel shaders) and not just slap on more "pipes". Currently we have a reasonable clue that this is what they plan to do with the r580 as well - it's basically the same as the r520 only each quad has 3x more pixel shader ALU's, and a revised scheduler to manage all those units. The number of TMU's stays the same, as does the number of ROP's.
 

aka1nas

Diamond Member
Aug 30, 2001
4,335
1
0
Originally posted by: keysplayr2003
Originally posted by: crazydingo
Originally posted by: Cookie Monster
IT was designed as a 32pipe line beast. Yield wasnt good enough, and power leakages, so it took a step back to 24pipe.

That is why sites like hkepc presumed the R520 would be 24 pipe, because there was engineering samples off it, and indicated to many it was going to be a 24 pipe card.

But still yields were bad, so 16 pipe, and this removed the yield problems, plus later on fixed the power leakage.

R580 is going to a 16pipe card with 3 ROPS per pipe, making it 48 fragment pipe card.
If such was the case, imagine the die space wasted. 32 pipe theory only existed in the cabinets of the rumor mills. :D

True. But also keep in mind that these rumors had a LONG time to gain momentum with all the waiting. So, it's going to take a while to go away. The X1800 series are 16 pipe cards without any disabled pipelines. (Repeating just for emphasis ;) )

I thought that they had to tape out r520 at least twice and during the new tape outs they dropped the pipe count.
 

Pete

Diamond Member
Oct 10, 1999
4,953
0
0
Originally posted by: Cookie Monster
IT was designed as a 32pipe line beast. Yield wasnt good enough, and power leakages, so it took a step back to 24pipe.

That is why sites like hkepc presumed the R520 would be 24 pipe, because there was engineering samples off it, and indicated to many it was going to be a 24 pipe card.

But still yields were bad, so 16 pipe, and this removed the yield problems, plus later on fixed the power leakage.

R580 is going to a 16pipe card with 3 ROPS per pipe, making it 48 fragment pipe card.
That whole first part is a joke, right? Ha ... ha?

hkepc & co. presumed whatever anyone would tell them. They didn't have the actual cards. Dave at B3D had been hinting for months that R520 was around 16 pipes, and we've had this rumor for almost as long:

R520 16-1-1-1
RV515 4-1-1-1
R580 16-1-3-1
RV530 4-1-3-2

Dave actually talked about this in his R520 preview. It's ROPs-TMUs per ROP-pixel pipes per ROP-Z-units per ROP.

That last part jives with what's been said. R580 will supposedly be like R520 but with three shader units per "pipe," so essentially three times the ALUs and thus pixel shader power. Each of ATI's R520 pixel pipes have 1.5 ALUs compared to a G70 pipe's 2 ALUs. So, very half-assedly:

R520 has 16pipes x 1.5ALUs/pipe = 24 pixel shading ALUs total.
G70 has 24 x 2 = 48ALUs.
R580 will have 16 x 3 (1.5) = 72ALUs.

Keep in mind that both R420/430/480 and NV40 had a similar config to R520, and G70 essentially doubled that. Then keep in mind that R430 and G70 are both 110nm. It's not ridiculous to think that 90nm will allow ATI to pack in more ALUs, especially given die size and power draw also increase.

As for the transistor counts, well, look at the die shot in B3D's review and you'll see the new memory controller hogs a lot of space. I doubt the thread dispatcher came cheap, either, and moving from all FP24 to all FP32 added quite a bit to each PS. They also added two VSs.

R520 has 16 "pipes" and G70 has 24, end of mystery. Neither company are rich or stupid enough to set out to sell chips running at only 2/3 capacity, and I don't think they're nimble enough to set out to make a 32pipe card, actually tape it out, and then quickly reduce the pipes by half.

Originally posted by: Genx87
Somehow people on Beyond3d have convinced themselves a GPU within the same generation will come out with 3 times the pipelines.

Makes a lot of sense if you ask me ;)
I hope we'll both be pleasantly surprised. The fact is that the 16-1-1-1, 4-1-1-1, 16-1-3-1, and 4-1-3-2 numbers appeared a long time ago, and so far three out of four are dead on. When you're behind (like ATI was basically since NV40), you're kind of forced to pull a rabbit out of your hat (like NV did with NV40).

The crazy thing is that both ATI and NV are rumored to release their DX10 GPUs by next winter, to coincide with Vista. That means R600 and G80 in a year!
 

Genx87

Lifer
Apr 8, 2002
41,091
513
126
Guess if we are now counting ALUs as the definition of a pixel pipeline it is possible. As your alluded to the current 7800 = 48 ALUs.

But I think that is probably stretching it a bit isnt it?

 

Pete

Diamond Member
Oct 10, 1999
4,953
0
0
Well, as we move to more and more shader effects, GPUs are going to need more and more shaders. No way around this, really. And so we'll have to get more technical in how we define a pipe. NV started by decoupling the ROPs, now ATI decoupled the TMUs. RV530 seems to have decoupled the pipes from the pipes, and R580 promises more of the same. :)

I'm not counting an ALU as a pipe, but it is becoming a pixel pipe's main feature. An ALU is essentially a shader, and we talk of pixel shader and vertex shader pipes, so it's not too much of a stretch to look beyond the "pipes" to the shader units themselves. I'm saying 48 shaders, not shader pipes.

Actually, isn't Xenos three shader engines (super pipes?) with 16 ALUs per, so 48 shaders total? We're probably going to see more and more ALUs per high-level unit, especially if games tend toward the 3:1 shader op:texture op ratio both nV (see NV40 previews) and ATI (see R520) predict.