agp fast writes
 

I have a geforce 3 ti200. are fast writes supported for this card? I would assume they were but my status says otherwise. My Motherboard supports them, but i figured my card would be more advanced than the motherboard...

[root@localhost xmame-0.72.1]# cat /proc/driver/nvidia/agp/card
Fast Writes: Not Supported
SBA: Not Supported
AGP Rates: 4x 2x 1x
Registers: 0x1f000007:0x0f000104
[root@localhost xmame-0.72.1]# cat /proc/driver/nvidia/agp/host-bridge
Host Bridge: Advanced Micro Devices [AMD] AMD-760 MP [IGD4-2P] System Controller
Fast Writes: Supported
SBA: Supported
AGP Rates: 4x 2x 1x
Registers: 0x0f000217:0x00000104
[root@localhost xmame-0.72.1]# cat /proc/driver/nvidia/agp/status
Status: Enabled
Driver: AGPGART
AGP Rate: 4x
Fast Writes: Disabled
SBA: Disabled

...
 

I have a Geforce 3 TI 500 from Leadtek... it says in the doc that it supports AGP fast write... well my driver reports that my card do NOT support fast write... I read somewhere on the net that some board manufacters lie about the specs of their cards... because nobody will check.

Have you checked your kernel config? I belive you have to enable the fastwrite in there.

Kernel config?
 

I don't see where we can enable/disable AGP fast write support in the kernel config! Do we have to modify the kernel source before compiling it, or do we have specific options for the agpgart module?

The NVIDIA Linux driver disables AGP fast writes to improve stability on buggy chipsets; you can enable them (at your own risk) using the NVreg_EnableAGPFW kernel module option.

I know but...
 

... I was takling about the fact that the driver reports through the /proc filesystem that my card does not support it. The documentation of the card says it supports fast write. I don't think it is related to the enable/disable fast write option of the nvidia kernel module... well... I hope so...

The AGP capabilities reported in /proc are read from the card's AGP status register; if you want to make sure that this status has not been altered, check the status file after a clean reboot (before X is started).

Checked
 

I checked, /proc/driver/nvidia/agp/card reports that my card does not support fast writes... I think it is a tricky bug in the driver or a hidden setting or my graphic board manufacturer is a bloody lier(leadtek).

If you suspect a tricky bug in the driver, you can look at PCI config space (lspci -xxx) after a clean reboot without the (NVIDIA, AGPGART) driver(s) loaded, the AGP status register is found there.

Done...
 

I checked... nope my card does not support fast writes. I checked the registers and the right bits.

Then LeadTek lied about its board! What should I do?

AGP fast writes won't buy you much, if anything, in terms of performance; since they might adversely impact system reliability, however, you should probably let it go.

OK... but...
 

... a lie is still a lie... and this one may deserve something... anyway LeadTek won't see my money anymore and I will spread the word.