Is SCSI Still the Fastest?

[Ensign]

In the good old days to get the best "on the fly" capture and transfer of video from a source into a computer. One was told to use a SCSI drive.

Does that still hold true

Or has SCSI been surpass by USB - RAID - SATA and other types of HArd Drives.

I just want to know since I might be able to get ahold of a SCSI drive soon.

[redwudz]

It probably still is, but a SATA ll RAID 0 likely comes very close. SCSI drives are generally small in capacity, fairly expensive and need a special controller and cables.

Here's a good article on the comparison: http://www.tomshardware.com/2003/11/14/raidcore_unleashes_sata_to_take_out_scsi/

[Skith]

You really won't be able to take advantage of SCSI unless you use multiple drives under specific circumstances (a server for instance). For personal use, SCSI is a waste of money, as a good IDE/SATA setup will give you equal or superior performance in a desktop setup.

[free is better]

In word YES. I migrated to scsi because i was experiencing sync issues when i captured. the journey is kinda interesting. i began with a p3 dual cpu machine, 512 mb, ide drive and an ati aiw pro. i could barely capture at scvd resolution so i built a faster machine (amd xp2100) and used a leadtek 2000 deluxe card. captures improved but still experienced random sync issues. it was arond this time that a co-worker told me that he been using nothing but scsi for years. bottom line is that after a year of learning how to use scsi, i am back to my first system but added an adaptec 39160 scsi controller and 4.3 gig u160 7200 rpm drive for the operating system. i now capture full dvd resolution at a bitrate of 6000 to an external 250 gig usb drive. if you invest some time to learn how to use scsi,you can take advantage of the abundance of deals that are out there. i just picked up 2 of the above 4.3 drives for $7.98 each, i got the card on ebay for $60 but you can get a 2940u2w for $20 which i use in the amd machine with a seagate cheetah 18 gig 10,000 rpm drive which i bought for $30. my explanation is the reduced load on the cpu caused by utilizing a separate controller for drive transfer frees it to concentrate on the capture. the benefits to other operations are likewise improved. increased drive speed as in the case of the cheetah drive makes it even better. i will never go back.

[edDV]

What are you trying to capture? Explain your goals.

Sorta like asking if a mainframe is still good for doing your taxes.

[whitejremiah]

scsi drives are HORRIDLY expensive in comparison to the IDE counterparts...and provided you have a relatively decent computer (this is where using something archaic like a p3 just completely fails....you couldve probably upgraded the motherboard and processor for what you paid for that scsi drive) it shouldnt make a huge differance..........just to give you an idea, i just paid 70 bux for a 250gb IDE harddrive....

[edDV]

...
if you invest some time to learn how to use scsi,you can take advantage of the abundance of deals that are out there. i just picked up 2 of the above 4.3 drives for $7.98 each, i got the card on ebay for $60 but you can get a 2940u2w for $20 which i use in the amd machine with a seagate cheetah 18 gig 10,000 rpm drive which i bought for $30. my explanation is the reduced load on the cpu caused by utilizing a separate controller for drive transfer frees it to concentrate on the capture. the benefits to other operations are likewise improved. increased drive speed as in the case of the cheetah drive makes it even better. i will never go back.

This is so Y2K.

Been there, done that. My Adaptec 2940U2W cost me $300 and 4GB ond 9GB SCSI Cheetahs were $500 to $1000ea. back then.

They can be made to work for up to 6-9 MB/sec single drive transfers (more with RAID 0) if you learn the ropes but a single current generation EIDE Maxtor, WD or Seagate HDD will beat that with 40-55 MB/s sustained transfer. Raptors will do 55+MB/sec. (MB = MegaByte)

Many if not most used SCSI drives come out of servers and have seen extreme duty. 5 yrs ago they used to swap and sell them at the point where MTBF statistics predicted failure.

[akito8]

http://storagereview.com/articles/200601/WD1500ADFD_3.html

For most work, I am guessing that a WD4000KD would do nicely but if you need the speed, I guess I'd step up to raptors, then a scsi drive...

since this has to do with capturing, I am guessing that you should look at sequential sustained transfer rates...

[anitract]

Generally scsi drives are used in servers. I think that in most cases its overkill for video capture. It might help in certain instances though. Unless you can get the drive & such at a very good price, I'd stick with the cheaper routes...sata, ide...they'll work just fine.

[SHS]

SCSI has not been surpass by USB - IDE - IDE/SATA RAID - SATA 1/2 if on high end server mother which has be 64bit slot which still 2 1/2x faster then USB - IDE - IDE/SATA RAID - SATA 1/2 which are base on PCI bus performance but most today harddrive can push 70+MB/sec which dose not even come close to what SCSI can do but as whitejremiah point out it HORRIDLY expensive in comparison to the IDE counterparts.
Also as free is better point out for personal use, SCSI is a waste of money, as a good IDE/SATA setup will give you equal performance in a desktop setup but depend on harddrive technology you go with traditional harddrive are slow vs next-generation solid state hard drive which highly more reliable but they even more HORRIDLY expensive in comparison to the SCSI/IDE counterparts.
Oh there lot keys facter you have take in count for in order to get highest transfer rate over PCI bus.

[edDV]

When you look at single drive performance, SCSI and ATA133 PATA/SATA sustained transfer speeds are limited by the drive itself not the interface. In all cases there is a maximum (outer)-minimum (inner) transfer rate as measured in the Storage Review article. Data capacity on a platter and other internal drive specs allow variable performance of drives in seek time and inner/outer sustained rate ratios.

The Raptor is a server style drive design with a SATA interface and achieves sustained transfer rates similar to that class drive.

RAID design can optimize for sustained rate or seek time based on application needs. Servers generally need fast seek times and only bursts of data. Video servers need sustained rate optimization especially when working with multiple SMPTE-259M uncompressed synchronized transfers*. In most cases, video servers are using fiberchannel controllers not SCSI any more.

At the other extreme USB2 drives appear to produce much slower seek and sunstained performance compared to internal ATA-133 or SCSI. Most prosumer editing packages have drive evaluation utilities to qualify a particular drive. In all cases that I have seen, USB2 drives run in the 9-20 MB/s sustained range where the same drive runs 40-55 MB/s when connected ATA-133.

Looking at computer "video capture", all the drives and controllers discussed above can handle 8-34 Mb/sec (~1-4MB/s) rates needed for MPeg2 or DV capture although USB2 drives have less safety margin and are more risky for CPU contention. Uncompressed YUV capture needs sustained performance from ~160 Mb/sec (640x480, 59.94fps) to 270/360 Mb/s SMPTE-259M C/D or (~20-45 MB/s). Single drive capture at these rates is risky but can be managed by placing capture partitions at the outter edge of the drive. Industrial strength design requires an optimized RAID and multiple drives.

Bottom line. A typical video capture application does not require, nor will benefit from a Raptor or SCSI server class drive. Save your money or go for a higher capacity PATA/SATA drive instead.


*true "realtime" uncompressed editing needs 3-4+ synchronized simultaneos SMPTE 259M SDI streams (>100 MB/s) and is out of the question for a single drive.

[RoopeT]

Without knowing your goals, here's an example:

When I had a Duron 800 MHz processor I couldn't capture full frame (720x576) huffuv ... it didn't matter if I used my 7200 rpm PATA (Seagate Barracuda IV) or my 5400 rpm PATA (Samsung)

After I upgraded my processor to Thunderbird 1200 MHz I could capture full frame huffuv ... and it didn't matter if I chose a 5400 rpm or a 7200 rpm drive.

Any computer bought after y2k will do, and any HD bought after y2k will do ... it might require some tweaking and experiments with different software / drivers, though.

If you're capturing DVB (or even HDTV-DVB) / MiniDV through firewire the bitrate will be even lower ... HD speed won't be a problem. (You might have to tune up your system in some other ways, however ... it's not a good idea to automatically start up a virus scanner when you're trying to capture something ... if you want to be safe (assuming windows) you'll need to turn off automagical updates, disable some of the services ...

[Ensign]

Thanks for all the answers.

The reason that I asked about SCSI drives in the first place is that I need to get a new (Re; USED/CHEEP!) ISA SCSI card for my scanner. And,since the card has a internal SCSI connection, I was just wondering if getting a SCSI drive just for video work would be a good idea.

I have already updated my MB (with SATA connections) and have a AMD Anthlon 64 bit CPU. So it could be in the end cheeper/easier to go the SATA route. But, as I stated above, since I have to get a SCSI card anyway. I thought I would "kill 2 birds with one stone."

[akito8]

ugh.. ISA - well I am guessing that since you upgraded your motherboard you do not have to get ISA anymore =) Does your scanner have the high-density 50pin connector or the super-old centronics connector? (I am guessing you are keeping the scanner b/c it is either heavy duty or legal - tabloid size)

If it is the HD50pin, I'd suggest the Adaptec AHA 2940 (not the UW or U2W versions - they have 68pin external)

yah, get a SATA drive.

[mikiem]

Another stupid question on my part I guess, but is the scanner that nice that an SCSI card is worth it? I mean, with bulb life now days at 3 years or so, and many non-replaceable...

[Wile_E]

Three words... Serial Attached SCSI (SAS). SCSI has major benefits in an enterprise environment. I work with 10K and 15K drives daily. These are the real performers. Although for video capture and basic home use, SCSI is overkill for most people. I currently have 7200RPM ATA133 drives. Fast enough for DV and RAW captures.

[SHS]

Ensign you be better off get new scanner in fact why not go for all-in-one Multifunction Printer + Scanner.
You meed to know what SCSI interface you have
DB25-pin (A lot scanner that had this interface) and all need is Adaptec AVA-2906
Centronics 50 pin (Found on high-end scanner interface) you can get per-made Cable or Adapters Connector to go below interface
HD50, Micro-D 50 pin
HD68, Micro-D 68 pin

[Ensign]

First. a Correction:

I need to get a new (Re; USED/CHEEP!) ISA SCSI card for my scanner

It should have said PCI SCSI card, which I have found a used Adaptec for $3.99 - and a DB25 to HD50 adapter for $11.10

As for why I want to keep my scanner?

MONEY

I can't afford a new scanner, especially since I get laid off 2 day after buying my new MB/CPU/MEMORY So, spending $15.09 is alot cheeper then getting a new scanner or scanner/printer.