Is Promise Ultra66 really necessary or is it hype?

[Dennis the Menace]

I have an ATA33 motherboard and I am looking to install a secondary HD for video storage - most likely the Maxtor 27.2 GB DiamondMax 6800 with ATA66. I have read a few articles recently which suggest that the Promise Ultra66 PCI Controller really doesn't boost performance by all that much. Has anyone tested an ATA66 card on an ATA33 board with and then without the Promise Ultra66? I am strapped for PCI slots and I would probably have to drop my DVD decoder card and install software decoding for my DVD drive. Thanks.

[Michel Carleer]

Depends on what you want to do with it. If you want to use it for any work that needs continuous streaming in our out of the HD, then you are out of luck because the transfer speed is essentially limited by the rotation speed of the HD times the linear density of bits per unit length. Given that the density is almost a constant for most current drives (it mostly depends on the technology of the R/W heads), the rotational speed is the important factor. At 7200 rpm, a current HD just come close to the speed of ATA33.
On the other hand, if your app uses the HD in bursts, then the ATA66 interface will boost performance. But what improvement you will be able to get will depend on the size of the HD buffer and the quality of it's read-ahead algorithm.
I have been able to verify this with my 2 IBM 7200 rpm ATA66 drives: when using them in UDMA2 (ATA33) and in UDMA4 (ATA66), the difference was only of the order of 2-3 % in sequential read and write tests. The tests were performed with a HotRod card. Both ATA33 and ATA66 were conducted with the same interface and same cable by simply reconfiguring the drives to be ATA33 or ATA66 compliant. You have to be aware that for reasons of instabilities when used on ATA33 interfaces, most ATA66 HD can be reprogrammed to be ATA33. Moreover, a lot of them are programmed as ATA33 when you buy them. Most HD manufacturers have a small DOS utility which enables you to change this ATA mode very easily. IBM certainly does.
The SCSI disks are a little better because they now run at 10000 rpm. But if you really want to improve on the sequential access speed, the only good solution for now is to build a RAID system in which 2 or more HD drives are used in parallel.
Michka

[Dennis the Menace]

I plan on using the system for digital video editing, using either the DV500 or the RT2000. I currently have a Dell XPS R450 PII with 128 MB RAM, with a 17.2 GB ATA33 5400 as my current boot drive. Any suggestions?

[Michel Carleer]

Sorry, I don't know the actual bandwidth required for the DV500 or the RT2000. The cheapest is probably to buy a 7200 rpm HD. The most sensible, as I mentionned in my previous post, is to go for a RAID system with two or more HD working in parallel. Unless you have a lot of money and go for professional disks which spin faster on very special SCSI interfaces (fiber interface, whatever that means).
You should find out the bandwidth needed by your DV setup, and go ask more info on forums devoted to HD systems (sorry, no known URL).
Michka

[This_Idiot]

Check out both the DV500 and RT2000 previews on the site. (www.desktopvideoworld.com)

Both solutions use the standard DV datarate (3.6Mb/s) and therefore a standalone defragged UDMA33 drive should be fine without resorting to raid arrays or UDMA66 controllers. To put it into perspective, 3Mb/s is the maximum rate at which the Rainbow Runners/Marvels can officially capture, giving an MJPEG compression of 6.6:1 for full frame.

[Michel Carleer]

Chris,
I do agree with you that for capture in MJPEG or DV, a good defragged ATA33 is more than enough. If you want to start doing some capture or editing in true color, then the speedier raid array becomes important.
Anyway, I think I lost the meaning of the question in the middle of my answer and started to try to explain what the different solutions are if you need a very fast HD system. Thanks for putting me back on track.
Michka

[Askalon]

ummm..if your thinking of going raid setup see the thread in this forum on turning your ultra66 to a fast trak66 seems that it should also work for a ultra33 to fast track33...if however you do not want to do this and want to get a regular fastrack, id be interested in the ultra33

[Chet]

Dennis
This is my experience with the Promise UDMA66 controller. I wanted to try something before I wrote back. I bought a Maxtor 7200 rpm UDMA66 drive. My motherboard didn't support the 66 and there were no new drivers on mob page. The drive wouldn't even stay in dma transfers and Matrox HD benchmark was showing 3.8 to 4.4 mb/s. I was getting a ton of drop frames with the new drive and alomst none with the udma33 drive already in my machine. I bought the Promise udma66 controler and the new drive now runs in udma66 and the bench mark test shows 9.1 mb/s transfer and I'm back to 2 drop frames in a 20 min. capture. That's my experience. I equate this, at least in my situation that the Promise card was worth it because the new drive wasn't worth much without it. The new drive is (according to bench mark) a marginally faster drive than my udma33 so if you can get your new drive to work in udma33 already I don't think you'll see much improvement.

Chet