Yup no doubt you are losing a lot because of that adapter, though it may also be due to the GTS450 being simply too powerful even for the Tualatins and they simply cannot move data to it fast enough. (Essentially CPU bound)

What is CPU usage when playing the video?

PCI bandwidth is shared so you may not really attain 266MB/s. On the other hand, playing 1080p video with such an old CPU certainly won't be an easy task... I recall seeing my own systems with P3 as well as Athlon XP struggle to get videos of such resolution played smoothly, even with an AGP video card that's considered good enough... Some effort to optimize the decoding code path against older CPUs that predate SSE2 or even SSE might be needed.

Besides, a PCI-X to PCIe (x4) adapter is theoretically possible using PEX8114 in the same manner as PEX8111/PEX8112 but no one is actually making one, as PCI-X is not as common as standard PCI.

Cpu usage is around 33%
There is no shared bandwith as I am using a PCI-X connector.

That is why it is strange and I am asking for help.
People here was able to play 1080p with a Crystal card. I assume a GTS 450 has much more power and features.

Can watch 1080 on Pentium III?

Comparison of graphics cards on a 1.4 GHz Tualatin

Re: High end PCI video card for Tualatin?

No, the problem is elsewhere.
Maybe my adapter is not really working at 66Mhz? Seeing the results of last link make me think this.
How can I check?

What plx is the adapter using. Looking at the spec sheet will tell you if it supports 66Mhz or not.

Is there a setting in BIOS that lets you set the speed of the PCI slots?

cyclone3d wrote on 2023-02-23, 04:23:

What plx is the adapter using. Looking at the spec sheet will tell you if it supports 66Mhz or not.

Is there a setting in BIOS that lets you set the speed of the PCI slots?

I am using a PLX 8111.
Maybe the 8112 uses 66Mhz?
No setting in Supermicro bios that tells me info about it AFAIK

Mamba wrote on 2023-02-23, 05:02:

I am using a PLX 8111. Maybe the 8112 uses 66Mhz? No setting in Supermicro bios that tells me info about it AFAIK […]
Show full quote

cyclone3d wrote on 2023-02-23, 04:23:

What plx is the adapter using. Looking at the spec sheet will tell you if it supports 66Mhz or not.

Is there a setting in BIOS that lets you set the speed of the PCI slots?

I am using a PLX 8111.
Maybe the 8112 uses 66Mhz?
No setting in Supermicro bios that tells me info about it AFAIK

PEX8111 and PEX8112 are the same from what I could find. On the other hand, it's really hard to tell whether the PCI bus is actually running at 33MHz or 66MHz... I never figured out how PCI bus speed works, as for PCI devices other than video cards, and maybe IDE/SATA cards, whether it's running at 33MHz or 66MHz don't really make much difference.

You'll need to check every PCI card installed on your system to see whether you have any card that cannot run at 66MHz. From what I've read, if you have at least one card that cannot operate at 66MHz it'll drag down the whole bus to 33MHz.

LSS10999 wrote on 2023-02-23, 05:56:

Mamba wrote on 2023-02-23, 05:02:

I am using a PLX 8111. Maybe the 8112 uses 66Mhz? No setting in Supermicro bios that tells me info about it AFAIK […]
Show full quote

cyclone3d wrote on 2023-02-23, 04:23:

What plx is the adapter using. Looking at the spec sheet will tell you if it supports 66Mhz or not.

Is there a setting in BIOS that lets you set the speed of the PCI slots?

I am using a PLX 8111.
Maybe the 8112 uses 66Mhz?
No setting in Supermicro bios that tells me info about it AFAIK

PEX8111 and PEX8112 are the same from what I could find. On the other hand, it's really hard to tell whether the PCI bus is actually running at 33MHz or 66MHz... I never figured out how PCI bus speed works, as for PCI devices other than video cards, and maybe IDE/SATA cards, whether it's running at 33MHz or 66MHz don't really make much difference.

You'll need to check every PCI card installed on your system to see whether you have any card that cannot run at 66MHz. From what I've read, if you have at least one card that cannot operate at 66MHz it'll drag down the whole bus to 33MHz.

It is true for shared slots. I have two pci-x slots and using only one.

I read on a voodoo forum that plx8111/8112 is not able to negotiate at 66Mhz, but a Pericom chip yes.
I assume I should find this (?)

Here some diffferences between 8111 and 8112.
Do not know if that can affect the ability to negotiate at 66Mhz

https://docs.broadcom.com/doc/pcie-pci8112-PE … conversion-r1-3

I am not able to find other adapters, the only Pericom I find do the other way around (pcie to pci).
🙁

The easiest way to check the actual bus bandwidth is to use Aida64 GPGPU benchmark. To be specific, the "memory read" and "memory write". With regular 32bit, 33 MHz PCI I got 110-120 MB/s. So if you are running at 66 MHz, you can expect > 200 MB/s.

Just a note - you need to have properly working OpenCL. That shouldn't be a problem with GTS 450.

Thanks will try this evening.

Here a link of a guy selling the pex8114 chip:
https://www.ebay.it/itm/111580009937?mkcid=16 … emis&media=COPY

Anyone here willing to produceva bunch of pci-x to pcie adapters? I am sure they would sell like bread…

The 8111 and 8112 should support running at 66Mhz.

cyclone3d wrote on 2023-02-24, 05:28:

The 8111 and 8112 should support running at 66Mhz.

Yes, they should. But I saw they not, probably the China adapters are too cheap.
Will check

Meanwhile I also found another suitable chip TSI384 by IDT
https://www.renesas.com/eu/en/document/dst/ts … re-sheet?r=5173

And it seems it is better than PEX8114, look at that read results!
https://www.renesas.cn/cn/zh/document/oth/per … and-plx-pex8114

But I fail to see any adapter used with that chip.

The PCI to PCI-E adapter is a bottle neck. Even though PCI-X can be 133mhz the PCI to PCI-e adapter isn't using all of those lanes. Its only using the 33mhz lanes. Its nothing like Nvidia AGP to PCIE bridge chips they used to put on some cards to make AGP gpus work on PCIE.

The Broadcom cards are dedicated silicon doing like 100% CPU offload of the decoding. Nvidia cards don't do anything like that. Even on a GTX 960 with somthing like a quadcore duo 1080P pegs the CPU.

You also have to render the video after decode, I had better experience with pot player because it has support for DXVA and I believe CUDA acceleration options.

A Gtx 450 has really High Driver overhead as well. Where the Driver lags the CPU and bandwidth.

You might want to try to find some native PCI card than can use 66mhz instead of trying to use a adapter.

Thanks,
Will try a HD5450 pcie over the adapter to see if has better decoding power.

havli wrote on 2023-02-23, 21:21:

The easiest way to check the actual bus bandwidth is to use Aida64 GPGPU benchmark. To be specific, the "memory read" and "memory write". With regular 32bit, 33 MHz PCI I got 110-120 MB/s. So if you are running at 66 MHz, you can expect > 200 MB/s.

Just a note - you need to have properly working OpenCL. That shouldn't be a problem with GTS 450.

Unfortunately I am not able to see any gpgpu benchmark option in AIDA64….
Final Reality bus transfer rate test gives me this results.
Not good…
2D 18.17mbytes/sec
3D 21.95mbytes/sec

There is something wrong here.

Mamba wrote on 2023-02-25, 16:38:

Unfortunately I am not able to see any gpgpu benchmark option in AIDA64….

Big red arrow should help :

Thanks,
Not that I am totally stupid…
I downloaded an old version of AIDA64 that is without gpgpu benchmark.

I dont know about that adapter but for that board to run the PCI-X slots at 66 MHz jumper pins JP13 must be open and from your attached picture it appears to be jumpered closed.