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A Look At the Fastest IDE Drive Yet
muks writes "Here's an article on Tom's Hardware about IBM's Deskstar 75GXP. It has some good points on why we still need UltraATA/66 and faster IDE interfaces while hard drive transfer rates don't keep up. "
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we didn't have these fancy namby pampy hard drives. We had cassete tape recorders to load and save programs.. And we liked it..
Now I feel old.
UDMA66 can have 4 devices per port. So, 8 devices on a standard system. Now, if they would just put more ports on a board, so overhead per chain stays fairly low, that'd be nice.
Or even a more wild dream: Make CPUs more efficent, instead of just faster.. Naa, never happen.. =]
75 Gig hard drives! (I feel really old, sometimes.)
"..don't you eat that yellow snow."
Complaints about an obsolete, bottlenecking technology on /.? Increadible? When somone says "X should DIE!" People say "what for, it works!" When people say "IDE should DIE!" people say "YEAH!"
PS> X should DIE!
A deep unwavering belief is a sure sign you're missing something...
Very nice... now how about some price comparisons:
IBM 20GB 75 GXP $136
IBM 60GB 75 GXP $417
Seagate 18.4GB X15 $482
(figures from pricewatch)
So that's over 3x the capacity for LESS THAN the
same price... SCSI rocks if money is no object,
but it'll still be a while before I build a PC
with it...
.technomancer
.technomancer
Yes, SCSI kicks the crap out of IDE, no argument there. But it is significantly more expensive. Like the other guy said, if you can afford it, great.
"Destroy science and religion. Science would re-emerge exactly the same; but not religion." - Penn Jillette, paraphrased
Actually this isn't the case, as holographic means that means the data is stored everywhere but in increasingly lower resolutions as you chop it up. That means access times are almost instantaneuos. According to Imation, they have already been able to achieve throughput in excess of 60GB/sec. For obvious reasons though, they are keeping the specifics of how it works under wraps. They are confident that a commercial holographic storage product should be available by the end of 2002.
www.enthea.org
I used to write SCSI firmware and the reason SCSI drives cost more is this, they have more features and functionality, fewer SCSI drives are sold each year causing parts to cost more. Also SCSI drives usually have lower areal densities so they need more disks and heads.
For example most SCSI hard drives support the following features:
Command Queuing and reordering, support restricted and unrestricted reordering
Mode pages which allow you to adjust the following:
Read-write recovery
Verify recovery
Caching
Logging
XOR controls
Send receive diagnostics
Skip read/write
And many more
EIDE has very few parameters that you can adjust so you have less code complexity. The sad thing is most operating systems don't take advantage of some of the features of SCSI. For example tag queuing is not taken advantage of in most operating systems. Windows 95 never sends a queued command and NT never really uses much queuing (less than 4 outstanding commands at most that I have seen in a bus trace) and if you think Linux does, think again. I looked at one device driver that only supported one outstanding command per initiator and some other UN*X's are not much better. We had to develop our own tools to get 64 or more outstanding commands to a disk drive to measure re-ordering performance gains.
I wish people would research the differences before making an opinion that has no credibility. Yes, Joe Blow user running Windows 95 won't see much of a difference running Word and Excel or playing UT, but a smart OS that understands SCSI will have significantly better IO and data integrity from disk to controller.
Just my $0.02
have more than 4 IDE devices without going to absurd lengths to do it. Nowadays, most folks have at least two CD type drives (a burner, a reader, a DVD, etc.), maybe an IDE tape, at least a couple of hard drives, and not enough money to go SCSI on everything. I don't need the arguments about SCSI; I accept that it is better, faster, more scalable, etc., but I don't accept the needless price gouging. I want cheap, relatively fast, and most importantly, more than 4 IDE devices.... Surely that's not so much to ask. If IDE is that bad off, let's quit using it
Windows is going the way of phlogiston...
We need to use a better bus/protocol. SCSI has a lot of advantages over IDE, and a couple of disadvantages, but here's my quick list:
Pros:
1. You don't waste all of that theoretical bandwidth like you do with IDE. A more streamlined protocol.
2. Despite the smaller protocol, it happens to be a lot more flexible - types of devices, NUMBER of devices, error recovery...
3. Did I mention that a UW SCSI bus can have 15 targets (i.e. drives) with one initiator (i.e. controller), while IDE is still stuck at 2 per bus...
4. Disconnect.
5. Smarter devices - they do more for you.
6. There is no pro #6.
7. Generally better warantees on hard drives (ok, not a technical detail, but a selling point).
8. Cable length.
9. CPU utilization (much better than ATA DMA)
10. It's fun to say.
11. Cheaper than fiber channel.
12. You can run it as a lan...
Cons:
1. More expensive controller.
2. More expensive drive electronics.
Still, well worth the money... plus, the better drives are always out for SCSI first, since they *are* the drives that go in even small servers (not your linux box/webserver/desktop/ftp server/Win98 box - a real server).
--
"It's tough to be bilingual when you get hit in the head."
On of the big sellers over here on the Mac end of things are IDE->Firewire cases. The flexibilty of Firewire devices and the cheap price of IDE drives.
More info is often posted over at Accelerate Your Mac web page.
Of course this brings the ire of us folks who want native (ie bridgeless) Firewire drives, but hey, you can't expect everything at once, right.
Pope
Freedom is Slavery! Ignorance is Strength! Monopolies offer Choice!
It doesn't mean much now, it's built for the future.
I'm about ready to buy a new system and recently looked into moving from SCSI to 1394... forget it. I still want 1394 for it's multimedia potential -- yes, those SONY Digital handycams with 1394 look real promising. But fiberchannel, 1394 ain't.
Frankly, why don't people use a two tiered approach with their systems. Folks here always degenerate the argument into an either/or debate. Either Linux or Windows, either GNOME or KDE, either IDE or SCSI; what bullshit. I use SCSI for boot and swap, and IDE for cheap storage. Do I need gigs of mp3's on a fast boot disk? No. Do I want my OS and swap on a set of chained master/slave IDE drives, with all the known contention this involves? No.
Use both to your advantage. You'll love the system speed of SCSI for what really counts, and the savings of IDE for what's a little less important.
- Total I/O per second: X15 117% faster
- Total throughput: X15 116% faster
- Average I/O response: X15 53% faster
Thanks to Storage Review for the benchmark figures.And remember kids, maximum length on those UltraATA cables is 18 inches(!), versus a luxurious 12 meters for Ultra160 SCSI, which transfers data much more quickly anyway.
First of all disk cache isn't high speed cache like your CPU uses. Its cheap standard dram type memory.
You don't need 2mb cache. Its pointless on modern drives. What you need is at least two full virtual "tracks" worth. Since most OS's want to format the drive so that its less than 1024 tracks that means a large ide disk will need 2*63*255*512=~16m bytes just to hold a virutal track mapping. If the drive doesn't have that, then when you do a large request, it will span real physical tracks and it will take several revolutions to get your data while you wait.
Of course this much memory would add nearly $16 to the price of a modern drive.
The old (E)IDE/ATA vs. SCSI flamewar again. I can't believe it! All I have to say is BAH
Each have their own applications.
As far as new equipment goes, SCSI is FAR more expensive. Yes I know you can buy old 9GB SCSI drives for peanuts and hook them up in a RAID and beat the pants off of any IDE out there. What about new systems? What if you dont have space or cooling for 8 cheap scsi drives?
What about devices such as the TiVo that demand 30 gigs of storage in a single drive (not to mention the other electronics) to make a profit at $500? Try doing that, SCSI!
After this, it may sound like I'm pro-IDE but really I prefer SCSI. But I'm not a bigot either and like to give IDE its fair due.
I am quite impressed with ATA/100. I set up a RAID-0 with the HPT370+Raid ATA/100 controller which came built into my new Abit mobo and two Maxtor 20.5GB ATA/100 Drives with 4M cache each. There is one drive per chain per channel. Ive got 41GB of storage now and I'm getting burst transfers from cache of 170-180MB/s! (In other words, my max transfer is better than Ultra160 SCSI) Also, I will never need to add extra drives etc in this particular system, so SCSI doesnt have it on me there. To top it all off, all the files on this system that are getting shuffled around are in the neighborhood of 100K. It's all run through the cache. SCSI would have cost me an extra $1000 to get the same performance. That's all there is to it.
~GoRK
Ok, first off - I used to be a SCSI fanatic, my first hard drive was a 80 Meg ST1096N I bought with 2 years of savings for an Amiga 500. SCSI kicks ass in the server room, but it absolutely sucks for home use. Why, you might ask?
1. You don't waste all of that theoretical bandwidth like you do with IDE. A more streamlined protocol.
No, but there aren't any devices out there that are going to suck up all that bandwidth on the consumer side of the market, either.
3. Did I mention that a UW SCSI bus can have 15 targets (i.e. drives) with one initiator (i.e. controller), while IDE is still stuck at 2 per bus...
I dare you to try and get 15 SCSI devices from different manufacturers and different scsi revisisions running reliably on the same bus. I had a couple different hard drives and CDROMs on a wonder scsi bus - it was a wonder why and when it would work.
4. Disconnect.
It'd be great if devices would disconnect..
5. Smarter devices - they do more for you.
Great idea - works well with scanners - doesn't work so well when the devices start to compete and see who's smartest, which is usually done instead of them doing what they're supposed to. Doesn't happen with IDE.
8. Cable length.
Do you know how hard it is to find scsi cables and adapters in most cities - and how much you'll pay for them? UGH.
12. You can run it as a lan...
Now this is cool; We did this with some amigas back in the day. Of course, ethernet cards work better now :).
Overall, my experience with SCSI was hell on earth. Trying to make a scsi cdrom, burner, hard drive(s), and other goodies from different manufactuters work and boot Windows was hell on earth; I haven't had any such problems with IDE, the controllers are there, and I don't need more than 2 hard drives and 2 removable media devices in any box (I'll just buy another box and set up a server).
YMMV though.