will an 40 gb ata100 help capturing on its own?

[dancray]

hi ho,

I've been thinking about buying a new harddrive but I am not sure it will achieve my objective (capturing easily at 640x480).

I have a p-III 500 cpu/abit be6 m/b with an ata66 controller along with a 20 gb maxtor ata66 system drive. When I try to capture at 640x480 I get a lot dropped frames and I have to tweak my system which often involves rebooting a few times (I can capture at 320x240 easy)...so I was hoping if I get a new hd dedicated to capture only I might be able to get clean 640x480 captures.

What's my problem then, you ask?

Well in order for me to properly upgrade my system to take full advantage of a ata 100 drive, I need also to buy a controller as well (they are about $150 here in canada), so instead I was hoping to attach the new ata100 drive to my existing ata66 controller.

Will it be a complete waste to this or will I see better performance with one of these new drives even attached to a slightly slower controller? is it worth buying the drive alone for my purpose?

thanks from a slight financially constrained murcer



[This message has been edited by dancray (edited 29 June 2001).]

[LvR]

dancray

I am pretty sure that your mobo will be able to handle just about any drive you care to hang onto its IDE ports. The 100m spec is a burst speed spec anyway - you should be able to read and write at around 25 M/s on any ATA33,ATA66 or ATA100 controller continuously if the machine is properly set up with just about any "modern" disk you care to mention.

Depending on your compression/format choice, 640x480 should not be a problem for your current system either.

What format and compression are you trying to use?



------------------
Lawrence

[dancray]

thanks for the reply, so you believe that I will get an improvement in performance even without the proper controller (ata100)...cool

I am trying to use huffy 2.1 codec...not sure what you mean by "format" though. By the way, will I need to get a larger power supply if I try to run 3 harddrives.

[LvR]

dancray

Huff has a compression ratio of about 3 - therefore you will be generating a datastream of around 7M/s with YUY2 format captures - even the older 5400 rpm will be close to handling that.

By format I mean YUY2 or RGB. YUY2 generates lower datarates than RGB for a given framesize ie 640x480

Any improvement in capture performance you see will be due to the extra disk sitting on a separate controller allowing the disks to be talked to seperately and simultaniously by the motherboard.

As far as PSU goes - it depends on the quality of your current powersupply and may not be required. (I have a 250w supply running 4 7200rpm disks on a Intel815 mobo and a 1G Piii CPU with no sweat)

I would first try to get my system to capture raw video (either YUY2 or RGB ) at 640x480 (about 20M/s) without Huff in order to prove the ability of the disks.

------------------
Lawrence

[Dr Mordrid]

These are the data rates I've been getting in NTSC using Matrox "legal" formats;

YUY2+HuffYUV;

704x480: 11 mb/s
352x480: 6 mb/s
352x240: 3.5 mb/s

RGB24;

640x480: 27.1 mb/s

YUY2 is better to use because most analog cards derive RGB from it. Therefore, using RGB results in a double conversion:

YUY2=>RGB=>codec

instead of

YUY2=>codec

This makes YUY2 captures less resource hungry in many ways including CPU loading.

Dr. Mordrid


[This message has been edited by Dr Mordrid (edited 30 June 2001).]

[dancray]

thanks for the tips, I will get the maxtor 7200 ata100 next week...hopefully I will be getting performance than my existing 7200 rpm ata 66...despite not having a ata100 card. I'll keep you up to date...

mucho gusto