RRS RGB capture

[zxgianni]

Hallo Doc,
I've read many of yours answers about Matrox cards. I've a RRStudio with a PCI Mystique 220. With my old P200mmx I was able to capture at up to 320x240 RGB but I thought that the problem was the hard drive (Ibm daqa 3.2 GB). Now I have a P700@785MHz, Lex(Jetway) mainboard (Apollo Pro 133), 320 MB ram, Quantum Fireball Plus AS 40 GB and Yamaha724 chipset based audio card. Why can't I capture at above 400x300 RGB (not always)? There was no problem with my friend's Ati Rage Fury Pro (with Huffyuv 640x480, about 9Mbit/sec). Where is the problem, could I have an AGO card? Why Matrox give the setting 640x480 RGB? I have DMA enabled and my hard drive give at Matrox test about 20 MB/sec. Is it a low quality mainboard?
I've tested with many cap apps. Have I to update bios (I've 1.6RR)?Thanks Doc.

[Dr Mordrid]

The Matrox cards have fixed resolutions they support in RGB capture.

Also the max frame size of 640x480 requires a lot more disk performance than you have. The minimum is 27.1 mb/s, but you need more for overhead and the variations in speed across the disk from inner to outer tracks. A fast CPU cannot replace this.

I'd say you need a BARE minimum of 30 and up to 50 mb/s in order to use the entire disk for full frame RGB capture. No single drive can do that. The most economical solution is to set up a Fasttrak100 RAID card with at least 2 fast ATA100 drives.

You can cut that in half with HuffYUV, but that still comes down to over 20 mb/s counting overhead & insurance capacity.

Dr. Mordrid