New hard drives

[Mandi]

I am getting CheckDisk messages on both my main hard drive (well, one partition of it - a FAT32 partition where I keep my media) and my backupdrive (also FAT32, just where I drag copies of whatever for frequent backup.) I've decided they both ought to be replaced. Given that they didn't just flat out die, I'm going to be a little more thoughtful about what I get this time.

I was (am) very interested in getting a 74gB WD Raptor (and it's glorious 10,000 RPM's) for my main drive, for the OS. I dual boot, but that still ought to be plenty of room. (Or maybe cough up a little more for the 150 gB, whatever.) I'd pair this with a 750 gB drive for data, split into a couple partitions (that probably only make sense to me, LOL.) My present mobo has SATA capapbility, but only SATA 150. As the Raptor SATA drives are only 150 anyway, that seemed no big deal.

However, I've been rethinking the computer gear I've got, and I think I am going to rebuild my machine with a newer mobo I've got lying here gathering dust. It's SATA 3.0 capable. Am I going to be happier with a 7500 RPM on SATA 3.0, compared to a Raptor on the older SATA interface?

[Jeff]

I really don't know if you'll notice a difference between the old and the new SATA for a workstation. Figure the drives themselves are only capable of 50 to 85 MB/s. So the 150 MB/s point to point is plenty there for a while to come. That leaves you with speed to fill the drive's buffer. Does it make a difference if you transfer 16 MB at 150 MB/s or 300 MB/s... I'm not sure. I imagine it could add up in a database app where the disk is being pounded with tons of transactions and shaving a ms of IOwait might make a difference, but in a workstation situation I don't know it will make any noticeable difference.

[Mandi]

. . . so you're saying that as I will be working below the 150 threshold anyway, I might as well get the 10,000 RPM Raptor?

[PaulKroll]

Absolutely. Get the Raptor. Even at 10K rpm, it's not going to saturate that SATA-150.

[Jeff]

And I'd take a 10,000 RPM SATA-150 over a 7,200 RPM SATA-300 even on a SATA-300 connector as I believe for my usage as an OS drive the faster speed of the drive is more important than the faster speed to the drive's buffer.

[Kevin]

The RPMs really don't affect the throughput (much). The reason for the faster spinning is latency. When you are reading one part of the disk and you need data from another part the heads move which takes a few ms then they wait until the disk spins around to the right place which takes a few more ms. If the disk is spinning faster than that part is shortened.

The faster RPMs are mostly felt on a workstation/desktop when the disk is very fragmented. Higher RPMs are preferred in a server because in a server you have multiple users trying to read different parts of the disk all the time.

[Jeff]

When my Atlas 15K II failed recently, I could definitely notice the difference in the XP OS load time and a half second difference in program load time running from an Atlas 10K IV instead.

[Kevin]

When my Atlas 15K II failed recently, I could definitely notice the difference in the XP OS load time and a half second difference in program load time running from an Atlas 10K IV instead.

The booting of an OS (especially one as big as XP) will do a lot of seeking. There are so many libraries and other files that it has to load.

[Mandi]

Gah, this doesn't make my decision easier, people :confuz:!!

I decided to get the Raptor, just because I've been salivating to try it out for years. It's about the same cost as two high capacity drives (and I do have to get two) so I'm really just sacrificing capacity on the main drive . . . and I don't really have that much I stash on my OS & Programs drives - about 6 gB for Windows, and a slim Kubuntu install on another partition. I think 74 gB will cover me LOL!

...and in the end, I am sure Kevin will be right, that it's not very noticeable for someone with my computing habits LOL - but I'll have had a chance to give it a spin.

[Jeff]

...and in the end, I am sure Kevin will be right, that it's not very noticeable for someone with my computing habits LOL
If you need to justify the spend, you may have to clone it to a 7200 drive and run it for comparison. Then you'll definitely notice how much slower the 7200 is once you're used to the 10k. (Although I could probably say that about most components other than enough ram... when I upgrade a computer now it seems I'm usually, sadly, not struck with how blazingly fast it is, but if I try to then retask its predecessor I'm immediately struck with how slow that one was in comparison (holy cow, how did I ever think this old machine was fast enough!)

[Jeff]

Speaking of the value of buffer, I wonder how much value having a 2 GB cache on the drive controller would have, such as with one of these: http://www.areca.com.tw/products/pcietosas1680series.htm

What we really need one of these years is to get the whole OS, spool files, temp directories, and all program files onto a 10-20 GB RAM disk, with large BBU of course (and that's backed up in the background during the idle time for security)

[Kevin]

You are talking a lot of money there with Areca. I know because I am looking at setting one up myself. I am only looking at the ARC-1120 model and even that is a lot of money :\

BTW, the PCI-X models will only work in 3V PCI and PCI-X slots which means very few if any desktop motherboards will support them. You would want either a server mobo with PCI-X slots or a desktop mobo with an extra PCI Express slot.

The main reason I am looking at Areca is not the performance advantage but the ability to expand a RAID5 array without reformatting it. I can buy the 8-port 1120 and 4 drives then as I need more space I can add 4 more drives one at a time to get more space and the Areca will just grow the array accordingly.

[Jeff]

Yea, it's definitely <something> that you can get three complete dell desktops with ram, cpu, and monitor! for the price of one areca 1680 raid card. The $1200+ price tag for the areca with 2 GB cache is probably too rich for me, and I'll end up going with an Adaptec 3805 for $475, but with only 128 mb of cache... just don't know how much juice I'd get out of the massive vs. frugal cache on the raid controller for workstation use.

(I've been using SCSI drives forever, but now that I'll have to buy a pair of 15k 74 GBs, it seems like it makes sense to go to sas for forward compatibility; but there aren't any cheap sas controllers it seems. So I'll use the controller for a pair of 15k OS drives in simple RAID1 and then for a 6-drive RAID10 array of satas for data. I just don't trust windows to do my raid for me, even though these needs are probably fairly simple. I also need to look at the potential and pitfalls of sas expanders to see if I could run an 8-drive sata raid10 array as well as the 2-drive sas raid1 array no the same 8-port controller with sas expanders.)

[Kevin]

I don't have any experience with that model of Adaptec card but the last time I tried to use an Adaptec SATA RAID controller I was completely unimpressed. Ended up switching to an 8xxx series 3Ware card instead.

The Adaptec SATA controller was nothing like the Adaptec SCSI controllers of the old days.

[Jeff]

It's too bad I got off on the wrong foot with 3ware :( Years ago I made the mistake of matching my first 9500s with a tyan motherboard and wd 200jd drives and it would drop them like clockwork... or anti-clockwork. Had me tearing my hair out and left me with a bad taste for the 3ware since mostly I watched it rebuilding the array.

I've been fairly pleased with my existing adaptec 2820SA though I don't think performance is stellar... I'm just using it for three raid-1 arrays and for that the drives are the limiting factor and I've been pleased with it for the last couple years. (it doesn't hurt my perception that I mated faster and twice as many drives to the adaptec 8-port controller than the 3ware 4-port controller ;)

In the back of my head I also have the idea that mixing all adaptec scsi / sata / and in the future sas controllers has a better chance of not conflicting with eachother than mixing in 3ware and areca, but this may be voo-doo science.

[Kevin]

The Adaptec that I didn't like was an integrated:
Adaptec AIC-9410W SAS (Razor ASIC RAID)
However, now that I think about it my complaints were more related to the Linux driver for it than the controller itself. Therefore you may be fine with it in Windows.

I currently have a box sitting here using an Areca 1120, An Adaptec 2940UW (boot disk), and nForce IDE+SATA. All of those controllers have disks on them. Linux is happy.

[Jeff]

Thanks -- was just coming back to ask what specifically you didn't like! I haven't found too many people that say the adaptec sata controllers deliver really fast performance, and (partially on topic) I've also seen a number of comments dissatisfied with average performance from the zero channel raid cards.

Areca seems to definitely be the performance-darling of the enthusiast crowd; A month ago I had talked myself into biting the bullet for another few hundred $$$ for the top of the line, but then Tom's Hardware did a review which showed Areca's first entry into the sas market to be pretty average and perform below the competition vs. their history of stellar sata raid performance. So I'm not sure it's a good time for me to get started with the $,$$$ areca controllers, specifically needing a sas conroller for 15k drives.

[Kevin]

I got my Areca for good drivers and online expansion capability. It is nice that it has good performance but I don't really need that in this case.

[Jeff]

I am kind of surprised that adaptec wouldn't have decent linux support... I had thought that because of their size and oem integration they would. (since my workstations will become test servers, storage servers, etc. for me in 2-4 years linux support won't be an issue now for me, but it will be an issue a long time down the road, which is when driver support will likely be even tricker.)

[PaulKroll]

I'm late to this part of the party, but, a controller with 2 gig of cache is an interesting exercise, but a machine with 2 gig of extra ram will almost certainly use the ram for disk cache (if applications aren't using it) whether linux or windows, and would be available for application use of course, and would be around $60.

If you're already at 3 gig and any more wouldn't be used, especially if you're thinking linux, then go 64 bit and get yourself 8 gig or more. Drink in the RAM!

[Jeff]

Driver support :EG::ras1: In my case I'm waiting for fiery drivers for our color copiers (unless postscript drivers are timeless, and maybe don't need 64-bit versions? Will have to do so research to see if I can push myself over the 64-bit cliff, as I think you're right, that's where it makes sense to put the $$$, into a resource pool that is much more flexible to use)

Hmph! On 5/2/07 canon released a statement that there is "no plan" for vista 64-bit support for postscript drivers for either of our color copiers which are under 5-year lease with 3-years more to go.

I don't think there's any way around this since my main workstation needs to be able to print to these printers, so I'm stuck in a 32-bit world until 2011 or until EFI/Fiery/Canon decide to release drivers :( Unless I can find a way to get a 64-bit windows to print to a 32-bit printer driver.

[Jeff]

Well, now you've got me thinking.

I could go with vista 64-bit OS and 8 GB of RAM.
Then I could install Microsoft Virtual PC 2007 (free).
And then I could install Windows XP 32-bit inside the virtual machine to print with.

The software I use to design with runs on either xp or vista just fine (but sadly not max osx) so with the virtual machine addon that allows sharing files between host and virtual machine, this could be fairly seamless, if the virtual machine was fast enough. Then I'd be running one app inside the virtual machine while editing photos and such in the vista host with greater memory support.

[Kevin]

I'm late to this part of the party, but, a controller with 2 gig of cache is an interesting exercise, but a machine with 2 gig of extra ram will almost certainly use the ram for disk cache (if applications aren't using it) whether linux or windows, and would be available for application use of course, and would be around $60.

If you're already at 3 gig and any more wouldn't be used, especially if you're thinking linux, then go 64 bit and get yourself 8 gig or more. Drink in the RAM!

That is probably true. The only time I have seen people using gigs of cache in the real world was in a SAN environment where there were multiple systems connected to the array.

In fact I had access to one of those once. The last company I worked for had a 1.5TB EMC Symetrix with 8GB of cache. It was insanely fast but the point was that 20+ Sun servers could write to it all at once and it wouldn't slow down. It was one of the most impressive pieces of hardware I ever played with until it got repossessed :(

I can't imagine why a desktop computer would need more than a few MB of hardware disk cache. The controllers and the rest of the system just aren't that fast.

[Jeff]

I don't have any experience with that model of Adaptec card but the last time I tried to use an Adaptec SATA RAID controller I was completely unimpressed.
For better or worse, I just got this up and running today with 8 western digital 500 GB drives in RAID-10 on an adaptec 31205 controller:

Simpli Software HDTach:

http://www.islanddesign.com/temp/Adaptec-31205-RAID-10-array.jpg

SiSoftware Sandra

Benchmark Results
Drive Index : 199.27MB/s
Results Interpretation : Higher index values are better.
Random Access Time : 7ms
Results Interpretation : Lower index values are better.

Windows Experience Index
Current Drive : 5.9
Results Interpretation : Higher index values are better.

Performance Test Status
Run ID : Adaptec Array 2000GB (RAID, NCQ)
Platform Compliance : Win32 x86
System Timer : 3.58MHz
Operating System Disk Cache Used : No
Use Overlapped I/O : Yes
I/O Queue Depth : 4 request(s)
Test File Size : 2.00GB
File Fragments : 1
Block Size : 1MB

Detailed Benchmark Results
Buffered Read : 663.71MB/s
Sequential Read : 276.80MB/s
Random Read : 91.84MB/s
Buffered Write : 499.93MB/s
Sequential Write : 208.90MB/s
Random Write : 149.35MB/s
Random Access Time : 7ms

Drive
Drive Type : Hard Disk
Total Size : 1862.50GB
Free Space : 1289.87GB, 69%
Cluster Size : 4kB

Physical Disk
Manufacturer : Adaptec
Model : Array
Version : V1.0
Serial Number : E0E9CC8F
Interface : RAID
Removable Drive : No
Queueing On : Yes