Truform on ATi GPUs after Radeon 8500/9100

Discussion about old graphics cards, monitors and video related things.

Truform on ATi GPUs after Radeon 8500/9100

Postby swaaye » 2019-4-09 @ 18:43

I've been playing a bit of Return to Castle Wolfenstein lately, on Radeon 8500. Switched to Radeon 9700 Pro and saw the frame rate drop badly in some cases. I was playing on a Athlon XP 1800+ with AGP 4x at the time. For those who aren't aware, the Radeon 8500/9100 R200 chip is the only GPU with full Truform processing. The later chips do it at least partially in software and the speed hit can be tremendous, depending on how many models in view are being tessellated. I don't recall anyone testing it.

I found a scene with a number of tessellated NPC models, which causes a major speed hit on the 9700. I collected frame rate numbers across 3 platforms with 4 different GPUs.

-the same install of RTCW was used for all systems
-set to High Quality 1600x1200x32
-varied CPU speed with RMClock and Throttlestop
-Catalyst 5.8 on Windows XP SP3
(fw = AGP fastwrites, tf = truform)
AGP 0x (PCI mode), 1x, 4x, 8x and PCIe x16 tested.
Image


Thoughts:

One needs a rather fast CPU and a speedy bus to avoid a bottleneck with software Truform. The Core i5 2500K machine appears to max it out at a bit more than 2.4 GHz.

AGP 4x appears to be sufficient bus bandwidth, at least for the Athlon 64, but any less than that becomes a bottleneck. Software Truform apparently sends much more data to the GPU. From what I understand, Truform tessellation can be seen as a form of compression, as a way to avoid added bus transfer of more geometric data and you lose this when it runs on the CPU.

Also interesting is I noticed the Radeon 8500 appears to tessellate slightly more than the software TruForm by default. I suppose they reduced the tessellation factor to prevent the performance from being even worse.
swaaye
Moderator
 
Posts: 7486
Joined: 2002-7-22 @ 21:24
Location: WI, USA

Re: Truform on ATi GPUs after Radeon 8500/9100

Postby Scali » 2019-4-09 @ 18:57

swaaye wrote:Software Truform apparently sends much more data to the GPU. From what I understand, Truform tessellation can be seen as a form of compression, as a way to avoid added bus transfer of more geometric data and you lose this when it runs on the CPU.


That is not specific to TruForm, but is true for hardware T&L in general.
Namely, when you use hardware T&L, you store the geometry in object space in video ram, where it remains static.
For each frame, you only send the proper transform matrices and light parameters, and the GPU does the rest. So there is virtually no traffic going over the bus at all, eliminating the bottleneck.
If you have hardware TruForm, it's just a special case of hardware T&L, so you still keep the geometry static in vram.
However, when you have software TruForm, you need to process the geometry on the CPU for each frame, and send the updated geometry to the GPU over the bus each frame.

In general, TruForm and more advanced forms of tessellation can indeed be seen as a form of compression. But that is more about a different kind of bottleneck: if you want to have extremely detailed geometry, that takes a lot of vram. That breaks down in two ways:
1) You need to fetch more data per display area (because more polygons are used), requiring more vram bandwidth.
2) You eventually run out of vram, and need to page geometry in via system memory through the bus.
Scali
l33t
 
Posts: 4355
Joined: 2014-12-13 @ 14:24

Re: Truform on ATi GPUs after Radeon 8500/9100

Postby swaaye » 2019-4-09 @ 20:09

Scali that makes sense. I was digging through Beyond3D for info on Truform on these later cards and came across the compression concept of tessellation. I hadn't thought of it in those terms before.

It's interesting to me that ATI even tried to support it in software because the speed hit is so impractical for a Radeon 9700 era system. I think the added AGP traffic can even cause stability problems on the less than great Socket A chipsets of the day.
swaaye
Moderator
 
Posts: 7486
Joined: 2002-7-22 @ 21:24
Location: WI, USA

Re: Truform on ATi GPUs after Radeon 8500/9100

Postby Scali » 2019-4-10 @ 08:41

swaaye wrote:It's interesting to me that ATI even tried to support it in software because the speed hit is so impractical for a Radeon 9700 era system. I think the added AGP traffic can even cause stability problems on the less than great Socket A chipsets of the day.


It may have something to do with the fact that ATi tried to make tessellation their unique selling point (although the Matrox Parhelia also had advanced displacement mapping support).
They pushed TruForm for the 8500 series, so they may have felt obliged to keep supporting it, to save face (it's a standard feature in the DX8/DX9 API, known as N-patches... NV's equivalent is RT-patches).
They introduced a new generation of tessellation in the Xbox 360 GPU. The 9700 era may have just fallen by the wayside there. Perhaps they actually tried to add a new-and-improved tessellation system on that GPU (which they could have made backward compatible with TruForm), but for some reason it got cancelled (they do have render-to-vertexbuffer).

See here for the D3D documentation on these early tessellation methods: https://docs.microsoft.com/en-us/window ... primitives
They were dropped in DX10 and later because there was the geometry shader now, I suppose.
Scali
l33t
 
Posts: 4355
Joined: 2014-12-13 @ 14:24

Re: Truform on ATi GPUs after Radeon 8500/9100

Postby an81 » 2019-5-09 @ 23:46

I concur with the OP on being surprised by how cpu hungry this feature is. I've myself had recently built specifically a pc dedicated to trying Truform out, since I've never had a chance or funds back in the day. Knowing it was cpu-heavy in it's software implementation (and Radeon 8500 not being an option due to its lack of msaa), I went for a 9600 pro and a Core2Duo 6420 on a P5PE-VM. So, HL and its mods run fine up until tessellation level 4, so does Wolfenstein with it's few and far between enemies. Serious Sam though is mostly unplayable, even if you set the tessellation quality quite low. Same goes for Morrowind. Call of duty is also quite slow, though it's used for landmesh only from what I've heard. Soldier of Fortune 2's fps is insanely crippled by it without any apparent visual gain. UT2004 is borderline playable, with heavy fps drops whenever it's more than 2 guys on screen (also a very fast-paced game, so no chance to really appreciate improved character models anyway). All in all it seems that dropping HW support was an incredible marketing blunder on Ati's behalf, since it does seem like a nice feature for many of the slower paced games (HL, Morrowind).

Here's a fun old thread:

http://www.rage3d.com/board/showthread.php?t=33653686
an81
Newbie
 
Posts: 54
Joined: 2019-5-09 @ 23:20

Re: Truform on ATi GPUs after Radeon 8500/9100

Postby swaaye » 2019-5-10 @ 18:58

Yeah it is incredibly CPU heavy and also apparently floods the AGP/PCIe bus with traffic. I saw in your link that sireric mentioned it is done with software + hardware which is about as strong a confirmation of that as possible. Seems mostly software to me! I suppose it's possible a 9600 Pro could be even slower at it. I don't have one to mess with unfortunately.

I wonder if the 2500K + X850 XT could handle those other Truform games adequately. Heh.

I messed with Call of Duty a bit. I discovered a new problem with Radeon 8500 this way. lol. In the presence of some kinds of pixel shading in OpenGL, mip mapping can break. KOTOR and NWN apparently have the same problem with 8500. A lack of mip mapping of course causes extreme texture aliasing. Not pretty. The game was also kinda flaky with GeForce cards. I think it was exposing some AGP problems of nForce1.
swaaye
Moderator
 
Posts: 7486
Joined: 2002-7-22 @ 21:24
Location: WI, USA

Re: Truform on ATi GPUs after Radeon 8500/9100

Postby an81 » 2019-5-10 @ 22:42

swaaye wrote:Yeah it is incredibly CPU heavy and also apparently floods the AGP/PCIe bus with traffic. I saw in your link that sireric mentioned it is done with software + hardware which is about as strong a confirmation of that as possible. Seems mostly software to me! I suppose it's possible a 9600 Pro could be even slower at it. I don't have one to mess with unfortunately.

I wonder if the 2500K + X850 XT could handle those other Truform games adequately. Heh.

I messed with Call of Duty a bit. I discovered a new problem with Radeon 8500 this way. lol. In the presence of some kinds of pixel shading in OpenGL, mip mapping can break. KOTOR and NWN apparently have the same problem with 8500. A lack of mip mapping of course causes extreme texture aliasing. Not pretty. The game was also kinda flaky with GeForce cards. I think it was exposing some AGP problems of nForce1.


I am now again in the process of procuring an X800XL 512mb PCIe for an Ivy Bridge "Truform rig", one that will hopefully also be able to run those new ESRGAN-enhanced texture packs, because the 128mb 9600 is easily below 5fps with the RTCW one I tried today at 1024x768 4x MSAA. With the agp rig though, I was almost certain a C2D would be enough, seeing how those old posts had people with Athlon XPs complaining. What were ATi thinking releasing it in this state and advertising it as a 2.0 version too..?

Another observation, as per your Athlon XP tests, I am pretty sure a 9600 pro on a C2D averages well above 20fps, though I don't know what scene you've chosen for your benchmark (I've only reached the Catacombs so far in my current playthrough). So it does seem like it's mostly cpu bound already with a 9600pro at 1024x768 4xAA.
an81
Newbie
 
Posts: 54
Joined: 2019-5-09 @ 23:20

Re: Truform on ATi GPUs after Radeon 8500/9100

Postby an81 » 2019-5-11 @ 19:47

I benched SS - First Encounter, using the auto-demoMP0001.

1280x960, Anys. 8x (ingame), Truform - All models (otherwise enemy models aren't tessellated), driver texture filtering - High Quality.

N-Patches:

Maximum - Average FPS=12.7, Low sustained=6.9
High (default) - Average FPS=18.2, Low sustained=10.1
Medium - Average FPS=26.9, Low sustained=15.5
Medium+4xMSAA - Average FPS=23.2, Low sustained=12.3

Image

Truform-optimized models only/N-patches - Maximum

Average FPS=94.2, Low sustained=75.8

Image

Truform off

Average FPS=94.3, Low sustained=76.5

Image

It looks good enough on Medium, but it's not helping much during the really busy scenes as in this demo.
Last edited by an81 on 2019-5-12 @ 15:07, edited 2 times in total.
an81
Newbie
 
Posts: 54
Joined: 2019-5-09 @ 23:20

Re: Truform on ATi GPUs after Radeon 8500/9100

Postby swaaye » 2019-5-12 @ 00:55

Yeah that's pretty slow! Hopefully the X800 XL and Ivy Bridge shockingly change things. 9600 Pro isn't exactly a speed demon in general anyway. X800 XL has 3-4x the geometry and fill rate, hierarchical Z, etc.
swaaye
Moderator
 
Posts: 7486
Joined: 2002-7-22 @ 21:24
Location: WI, USA

Re: Truform on ATi GPUs after Radeon 8500/9100

Postby Standard Def Steve » 2019-5-12 @ 07:04

I've been doing lots of Haswell benchmarking on my HTPC lately. It's powered by an i5-4670K @ 4.4GHz. One thing I noticed while running memtest86 and AIDA64 is that Haswell's L1 cache is much faster than Sandy/Ivy's. Apparently Intel increased the L1 performance to keep the FPU fed while running AVX2 code.

However I've found the fast L1 to really shine in some non-AVX2 workloads too. Haswell is great for pushing absurdly high frame rates in old XP games. It's also a good bit faster than my 4.2GHz i7-2600K at emulation and benchmarks like 3DMark2000/2001. I'm pretty sure I still have an old X800XT somewhere. Could be interesting to see how much of an effect the greatly increased L1 bandwidth has on software Truform.
Standard Def Steve
Oldbie
 
Posts: 983
Joined: 2012-9-15 @ 08:04

Re: Truform on ATi GPUs after Radeon 8500/9100

Postby an81 » 2019-5-12 @ 15:09

swaaye wrote:Yeah that's pretty slow! Hopefully the X800 XL and Ivy Bridge shockingly change things. 9600 Pro isn't exactly a speed demon in general anyway. X800 XL has 3-4x the geometry and fill rate, hierarchical Z, etc.


I don't know, Ivy bridge isn't exactly 10 times faster than a C2D.
an81
Newbie
 
Posts: 54
Joined: 2019-5-09 @ 23:20

Re: Truform on ATi GPUs after Radeon 8500/9100

Postby an81 » 2019-5-12 @ 15:14

Standard Def Steve wrote:I've been doing lots of Haswell benchmarking on my HTPC lately. It's powered by an i5-4670K @ 4.4GHz. One thing I noticed while running memtest86 and AIDA64 is that Haswell's L1 cache is much faster than Sandy/Ivy's. Apparently Intel increased the L1 performance to keep the FPU fed while running AVX2 code.

However I've found the fast L1 to really shine in some non-AVX2 workloads too. Haswell is great for pushing absurdly high frame rates in old XP games. It's also a good bit faster than my 4.2GHz i7-2600K at emulation and benchmarks like 3DMark2000/2001. I'm pretty sure I still have an old X800XT somewhere. Could be interesting to see how much of an effect the greatly increased L1 bandwidth has on software Truform.


I don't think socket 1150 supports XP much, unfortunately.
an81
Newbie
 
Posts: 54
Joined: 2019-5-09 @ 23:20

Re: Truform on ATi GPUs after Radeon 8500/9100

Postby swaaye » 2019-5-12 @ 18:58

BTW I had to manually install Catalyst 5.8 on the 2500K, through device manager. The installer didn't seem to like the platform. Catalyst Control Center can be manually installed in the setup directory. There is also a classic control panel version of the drivers, which may be preferable because early CCC is pretty flakey.

5-8_xp-2k_dd_cp_wdm_25203.exe
swaaye
Moderator
 
Posts: 7486
Joined: 2002-7-22 @ 21:24
Location: WI, USA

Re: Truform on ATi GPUs after Radeon 8500/9100

Postby willow » 2019-5-12 @ 20:17

swaaye wrote:I've been playing a bit of Return to Castle Wolfenstein lately, on Radeon 8500. Switched to Radeon 9700 Pro and saw the frame rate drop badly in some cases. I was playing on a Athlon XP 1800+ with AGP 4x at the time. For those who aren't aware, the Radeon 8500/9100 R200 chip is the only GPU with full Truform processing. The later chips do it at least partially in software and the speed hit can be tremendous, depending on how many models in view are being tessellated. I don't recall anyone testing it.

I found a scene with a number of tessellated NPC models, which causes a major speed hit on the 9700. I collected frame rate numbers across 3 platforms with 4 different GPUs.

-the same install of RTCW was used for all systems
-set to High Quality 1600x1200x32
-varied CPU speed with RMClock and Throttlestop
-Catalyst 5.8 on Windows XP SP3
(fw = AGP fastwrites, tf = truform)
AGP 0x (PCI mode), 1x, 4x, 8x and PCIe x16 tested.
Image


Thoughts:

One needs a rather fast CPU and a speedy bus to avoid a bottleneck with software Truform. The Core i5 2500K machine appears to max it out at a bit more than 2.4 GHz.

AGP 4x appears to be sufficient bus bandwidth, at least for the Athlon 64, but any less than that becomes a bottleneck. Software Truform apparently sends much more data to the GPU. From what I understand, Truform tessellation can be seen as a form of compression, as a way to avoid added bus transfer of more geometric data and you lose this when it runs on the CPU.

Also interesting is I noticed the Radeon 8500 appears to tessellate slightly more than the software TruForm by default. I suppose they reduced the tessellation factor to prevent the performance from being even worse.

Morrowind support trueform with a russian software (fps optimiser I think). With a 9700pro, the perfs was very bad.
willow
Member
 
Posts: 122
Joined: 2012-1-07 @ 22:37

Re: Truform on ATi GPUs after Radeon 8500/9100

Postby Standard Def Steve » 2019-5-14 @ 05:58

Well, I found my X800XT, but it doesn't seem to be feeling too well. The graphics driver is frequently crashing.

I have two other ATI cards, but unfortunately they aren't anywhere near as powerful: a Radeon 9800 Pro and a PCI 9250 with 128-bit memory. I take it the 9250 is capable of hardware Truform?

I'd be testing both cards on this system:
PIII-S at 1628MHz
FSB=155MHz
AGP=77.5MHz, which I guess makes it AGP 5x. :P The 9800 Pro doesn't seem to mind at all.
PCI=38.75MHz, which should help the 9250 out a bit.

2GB of DDR RAM at 310MHz, 2-2-2-5 timings
QDI Advance 12T motherboard, VIA Aprollo Pro 266T chipset
X-Fi Platinum
XP SP3

Which scene were you using to test your machines?
Standard Def Steve
Oldbie
 
Posts: 983
Joined: 2012-9-15 @ 08:04

Re: Truform on ATi GPUs after Radeon 8500/9100

Postby Munx » 2019-5-14 @ 11:11

Standard Def Steve wrote:I take it the 9250 is capable of hardware Truform?

Its not. Only 8500, 8500LE and 9100, which is a rebadged 8500LE.
My builds!
The FireStarter 2.0 - The wooden K5
The Underdog - The budget K6
The Voodoo powerhouse - The power-hungry K7
The troll PC - The Socket 423 Pentium 4
User avatar
Munx
Oldbie
 
Posts: 508
Joined: 2015-3-21 @ 19:36
Location: Kaunas, Lithuania

Re: Truform on ATi GPUs after Radeon 8500/9100

Postby an81 » 2019-8-05 @ 17:56

Couldn't get my hands on an Ivybridge just yet, so instead decided to give that X800XL a run in a Wolfdale powered pc. Thought that it'd be interesting to see whether a 9600Pro was indeed bottlenecking a Core 2 duo and whether a faster card would make a tangible difference.

The systems are as follows:

C2D E6420, 865G, 512mb DDR@354, Radeon 9600Pro 128Mb
C2D E6420, G31, 2GB DDR2@800, Radeon X800XL 512Mb
C2D E8400, G31, 2GB DDR2@800, Radeon X800XL 512Mb

Windows XP SP3, Catalyst 5.8, SS:First Encounter, auto-demoMP0001

Image

Image

Image

So you do indeed get some uplift from using a faster gpu even in such cpu-bottlenecked scenario, but whether it's due to pci-e or faster ram, rather than X800XL's enhanced geometry processing ability, I don't know. I may run some more tests if I ever get a hold of a faster agp card for the 865g system.
an81
Newbie
 
Posts: 54
Joined: 2019-5-09 @ 23:20

Re: Truform on ATi GPUs after Radeon 8500/9100

Postby an81 » 2019-8-15 @ 20:28

Got myself a Radeon 9600XT 256mb.

Image

Image

I guess it does indeed need some raw polygon crunching power on the gpu to handle all the extra polys.
an81
Newbie
 
Posts: 54
Joined: 2019-5-09 @ 23:20

Re: Truform on ATi GPUs after Radeon 8500/9100

Postby lost77 » 2019-8-16 @ 21:59

Ran some test with a Sandy Bridge. Seems Direct3D is much faster and looks the same (to me anyway). Maybe old OpenGL has a lot of overhead.

Image
User avatar
lost77
Member
 
Posts: 118
Joined: 2018-9-24 @ 23:01

Re: Truform on ATi GPUs after Radeon 8500/9100

Postby an81 » 2019-8-17 @ 00:09

I haven't realized it also runs in d3d, just tried mine and it's indeed a lot faster. Also, which one is the Memphis demo?
an81
Newbie
 
Posts: 54
Joined: 2019-5-09 @ 23:20

Next

Return to Video

Who is online

Users browsing this forum: Auron359, MSN [Bot] and 3 guests