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IDE to SCSI Converters?
ericdano asks: "Addonics has announced a pair of SCSI solutions, which convert common ATAPI devices and IDE hard drives to high-speed SCSI devices on all Windows, Macintosh, and Linux-based computers: the IDE-SCSI converter ($100) for hard drives and the ATAPI-SCSI converter ($110) for ATAPI-based CDRW, DVD-R/RW, DVD-ROM or CD-ROMs. The company has also announced a high-performance single-channel Ultra160 SCSI PCI host controller ($170) with 160MB/sec. data throughput. How safe are these products?"
Yeah, right. By putting my old IDE disk in this controller it will be faster? Right.
Not that it couldn't be useful, but this is marketroid speak at its worst...
Nevertheless, when it comes to hard drives, the basic performance of the drive itself will be a limiting factor. I doubt your IDE drive will suddenly get a boost in performance, though it would be neat to see some Bonnie++ results to confirm this.
As for the SCSI controller, does anyone have any experience with these? Its a fair bit cheaper than the equivalent Adaptec model. After putting SCSI in my Linux workstation at work, I'm hooked on it: what's not to like about cutting compile times by 50%? Maybe I could get SCSI at home if this controller is the real deal.
their cards work fine for both atapi and ide in one card, they even have cards for 50 and 68 pin, plus lvd
at memorylabs for 74$ us
macena 61.90$ us
works like a charm, and is great for when you don't want to pay the outrageous prices they charge for scsi 40x burners for your older sun system, at least that's why my roommate wanted one
So they do work on other brands, just not necessarily guaranteed to work.
I think it would be pretty smooth if they also offered this IDE-SCSI converter in an SCA version. I'd pick up three just to try them out!
The page doesn't mention anything about tagged command queueing. SCSI drives can receive multiple commands from the controller simultaneously and return the results in whatever order they think is the fastest at that moment. ATA cannot do this, and this is a reason why SCSI usually 'seems' to be faster than ATA. Then there's the issue of latency; the converter would necessarily take some time to convert the commands between SCSI and ATA. Even with ATA/133, I suspect that an ATA drive connected to a SCSI bus using this converter will be much slower than a native SCSI drive. And, at USD$99, it cancels out any savings that you might get from buying an ATA drive over a SCSI one. It'd be better, though, if the converter allowed the user to connect two ATA drives simultaneously, instead of having to use one converter per drive.
In Soviet Russia, Jesus asks: "What Would You Do?"
Most scsi drives have a jumper you can set so they start when they receive a scsi start command from the controller. You configure the controller to send scsi starts to the drives in a sensable way. This way your 14 drives don't try to spin up at the same time and blow up your power supply. Remember it takes much less power to keep the platters spinning then it does to start them spinning. Most IDE drives just power up the moment you add power to them. A tower of 14 180 gig drives is impressive but a tower of 14 180 gig drives all trying to spin up at the same time would probably melt most server grade power supplies.
Any ideas how they get around this?
Bob.
Two 80G IDE hard drives : $200. /. : $4
Two ATAPI-SCSI adapters : $200.
A new SCSI controller : $170.
Time spent telling us about it on
Benchmarking the upgraded system and learning you took a 9% performance hit : Priceless.
Glonoinha the MebiByte Slayer
I've been running lots of SCSI drives under linux for a long time now. I started out with a single Adaptec SCSI controller, changed over to a pair of DPTs, then went back to Adaptec when I figured out that the Adaptec boards need lots of extra cooling. The drives have been scavenged from dumpsters of local companies; over the last eight years the insatiable corporate hunger for server disk space has driven them to denser platters, so they toss out the older 1 and 2 GB drives.
Then a friend gave me a case of 9 GB IBM ultra-SCSI drives (new, unused) he got as a going-away prezzie when the dot-bomb he worked for collapsed. Like you, I couldn't figure out how to case 'em.
Then I went to the local Mega-Mart (Where Shopping Is A Baffling Ordeal (tm!) ) and got some of that heavily perforated sheet metal that people pop-rivet to their screen doors to keep dogs from busting them. It comes in several patterns; if you choose carefully, you can get something that folds easily along straight lines, and has holes that line up reasonably well with hard drive mounting points.
I use tin snips and old case screws to make what I call "drive blocks", which are seven drives sitting vertically separated by half-inch gaps. I attach old screen-door handles to the top middle, and I make power cables with one female and eight male connectors. I have a bunch of large surplus 12 vdc fans that are ganged together two fans per power connector, and I repin them from 12v to 5v and attach them so they blow through the slots in the drive blocks.
Nowadays I am running linux soft RAID (RAID 5 across six drives with one spare, except for the boot partition which is just mirrored) on two drive blocks. I have CPU coolers on the Adaptec controllers, though, because they run so damn hot.
Unbelievably fast disk storage, and I have all the drive LEDs hooked up so it looks really cool when you do a large file copy or an fsck. The blocks sit happily on any flat surface, with their own small AT-style power supply, connected by SCSI and a ground wire to the rest of the server.
Be warned!!! These products are INCREDBILY DANGEROUS!!
These converters can cause Spontaneous Incinerations, Plague, Pestilince and Famine, Birth Defects, Sour Milk, Global Thermonuclear Annihilation, Premature Baldness, Tire Sidewall Blowout, Post-Traumatic Stress Syndrome, Acid Reflux Disease, Parachute Deployment Malfunction, O-Ring Seal Degredation, Spurious Airbag Inflation, Mass Hallucinations, Alien Invasion, Asteroid Impact, Genetic Mutations, and Loss of Balance to the Force!
Quando Omni Flunkus Moritati
The new line of IBM drives (I thought they got out, but apparently not) offer features like 8mb cache, and tag command queuing. While SCSI will still beat IDE in some way or another, IDE is getting closer.
As everyone else has said though, shoehorning IDE into SCSI won't change much. But, it does have one advantage that I can see. It might be cheeper to get one of these converters for an old SCSI system, like older Macs.
The speed of SCSI coupled with the unreliability of IDE. Sounds like a winner.
Seriously, you're not going to be using this in a five-nines server. But this device does have its place on desktops.
You can get a 60GB IDE drive for around a hundred bucks. Add this converter and you've got a 60GB SCSI drive for two hundred. True SCSI drives of that size are around $500.
Sure, you are losing reliability (and maybe some performance) over native SCSI drives, but what you gain is the ability to have more than three drives in a system (the fourth being your CD-ROM in an IDE system) and use cheaper drives on a decent hardware RAID array on a budget not backed by corporate pockets.
Some in this forum will bring up IDE raid adapters... they are almost all crap (Promise cards have given me nothing but trouble -- Adaptec's AAR-2400A is the best I've found).
Now it remains to be seen how reliable this controller is, but if it works well, I think it will be A Good Thing.
Give me my freedom, and I'll take care of my own security, thank you.