View Full Version : MDD hard disk configuration

09-10-2005, 08:18 AM
Dear List,

I have a Dual G4 MDD with four available internal hard disks and two ATA controllers on the motherboard. I want to install two 40gb drives as a RAID 0 for Photoshop swap, and the remaining two drives split between OS X 10.4.2 System files (on one drive) and /user files (on the other)

N.B. /user files consist of iTunes, iPhoto, Mail, etc, whereas large Photoshop files are stored on external Firewire drives

What is the best internal configuration here? (there are three possible)

1.) 40Gb + 40GB RAID 0 on ATA 66 bus/controller
2.) 40Gb + 40GB RAID 0 on ATA 100 bus/controller
3.) 40Gb + 40GB RAID 0 one each on each bus/controller

I have to assume that #3 ain't' recommended.

Thanx for any ideas/comments

09-10-2005, 08:29 AM

Check through the Photoshop Guide and FAQs. Quite helpful, you'll want to max out the RAM of course. I don't recommend using two ATA bus for RAID (they differ in thruput enough to make a difference) along with sharing the bus with the system on one side and /Users on the other.

A PCI controller (Serial but even ATA) would do better and go further. For drives to use in RAID, ideal is faster drives with better performance.

09-10-2005, 08:40 AM
yeah I read everything twice (thrice even).

Trouble is, my PCI bus is maxed out, no more room for another controller. So I'm stuck w/ ATA for now until I eventually upgrade to a G5.

maxed out RAM too. 2 Gb.

So, with internal ATA as my only choice (although I guess I could RAID some firewire drives -- I figured RAIDed internal ATA would be better/faster than RAIDed firewire) which way to go?

P.S. 120Gb Hitachi as OS and 250Gb Hitachi as /user


09-10-2005, 08:52 AM
With FireWire you would still need a controller, likely FW800.

I have two SCSI (ATTO UL3Ds) which let me run a large variety of 10k/15k drives for scratch and RAID. i would invest in SeriTek 2+2 (two internal and two external channels) as well as look at disk drive choices. The Maxtor Maxline III 300GB 16MB cache makes a nice fast drive.

Also, in the FAQ & Help forum, "SATA PCI Controllers" has some good information on what is available. Can't "sacrifice" one of those slots?

Most 40GB ATA drives are going to be much slower than newer additions and are not well suited for RAID.

Of course the ideal would be G5 PCI-X with 8GB RAM and still use Serial ATA for scratch. Something you could begin with and take forward.

09-10-2005, 11:42 AM
Thanx for the feedback.

Unfortunately, other pressing ($$$$) requirements must come first, the G5 will simply have to wait. There is no ROI in having the fastest mac on the block.

I guess I "could" throw out the Firewire cards and replace them with an 8-channel SATA card. Then I could RAID0 two SATA internal drives and use the remaining 6 channels as JBOD for my Photoshop projects. (see near-term goals below)

However, the main issue is NOT speed/performance (I don't need a dragster, I need a Ford F350!!!) Rather:

1.) printing times are the slowest single item in my total workflow (note: opening/editing/saving 1gb PS files is acceptable). Sometimes printing 500mb files to my 9600 takes 5 minutes for the spool file to build up. This is why I want to move the /user files. Perhaps there is other stuff I could do here to address this issue...

2.) backup/failover of data. I currently have 1Tb of valuable data (both clients and my own) stored on individual disks. So currently, backup to redundant (slow) drives is preferable to spending money on improving throughput

- Short term goal: get machine tuned as best as possible "as is"
- Near term goal: transfer current 1Tb data to RAIDXL, and backup 1Tb to JBOD (cheapest might be to re-user the existing 250Gb IDE drives). Would require TWO SATA controllers and TWO hot-swap Burly towers
- Long term goal: retire G4 and move to G5 architecture w/ 8Gb RAM, re-using the above drives (might require new controllers, we'll see).


09-10-2005, 12:06 PM
I would definitely clean up the boot drive and move everything else off to another drive. Printing can leave behind GBs of temp files which can choke any system. Isolating the system and Users is critical first step. Keep the boot volume 60% free space as well and allow for 30-40GB free space or more for printing and Photoshop.

ATA on MDD is better than previously but it is best to not have two drives that are concurrently used at the same time on the same bus. A backup drive, yes. However, I don't keep any drives in the ATA/100 cage to allow cooling.

The best setup I can see that would help would be two of the best ATA drives. Something like a set of Maxtor DM10 300GB $130 (http://www.zipzoomfly.com/jsp/ProductDetail.jsp?ProductCode=100719-5) w/ 16MB cache - and/or a pair of Hitachi Deskstar T7K250 160GB $79 (http://www.zipzoomfly.com/jsp/ProductDetail.jsp?ProductCode=100581-1) for maximum "Ford" performance. One for the system (100GB volume and 200GB for backup) and use the 2nd drive (150/150) for /Users and backup/archive. No RAID. The DM10 300GB is comparable alternative to the WD 10K Raptor drives in booting and performance.

(The reasoning behind partitioning is to use the outer tracks of the drive which are the faster region, and keep seek latency to a minimum.)

FireWire 400 has had too many problems to keep investing and using, FW800 seems better and can offer RAID (G4, not G5) and benchmarks are available on www.barefeats.com Hitachi 500GB (http://www.zipzoomfly.com/jsp/ProductDetail.jsp?ProductCode=100600) to gradually replace 250GB drives as needed.

There is a problem with multiple SATA controllers. That requires PCI-X. There are hot-swap trays for both FW and SATA.

There are links to reviews, benchmarks etc. In the "storage reference" section, too.

09-10-2005, 01:11 PM
The first and last thing I would be looking at is to replace small, older ATA drives. That is one of the easiest and cheapest, and essential, upgrades to make from whatever stock drive it came with. Just that will do a lot. Any drive with 2MB cache is going to be sluggish. There is no reason not to be getting 55-62MB/sec from a single ATA drive.

09-10-2005, 08:26 PM
Thanx for your valuable insight. It has really assisted me in "seeing" the real issues. Here is what I'm considering given your feedback:

Internal ATA Drives (re-use existing 250Gb 7200 rpm IDE drives)
<pre> Internal BUS 1 Internal BUS 2
____________________ ____________________
| Drive 1A (OS X) | --> CCC clone (manual clone after upgrade) --> | Drive 2A (backup) |
| Drive 1B (backup) | <-- manual mirror nightly <-- | Drive 2B (/user) |
____________________ ____________________</pre>
TEMPO-X eSATA X8 + Burly 8-drive, hotswap tower:

Driva 3A (live) --> automatic mirror --> Drive 3B (Backup) - 300Gb SATA each
Driva 4A (live) --> automatic mirror --> Drive 4B (Backup) - 300Gb SATA each
Driva 5A (live) --> automatic mirror --> Drive BB (Backup) - 300Gb SATA each
Driva 6A (live) --> automatic mirror --> Drive 6B (Backup) - 300Gb SATA each

Giving me a 1.2 Tb live disk space + 1.2 Tb hotswap backup for well under $3000.
The only issue left is what to do with a Photoshop scratch file, which is probably not critical. (perhaps just firewire 400 would do?)

Firewire External
RAID 0: (Drive 4E + Drive 4E) (re-use existing 200Gb IDE each) Photoshop scratch

Note that I've no longer considered the old 40Gb drives. Thoughts?


09-11-2005, 07:53 AM

Great diagrams! Really helpful to see your plans. (I wasn't sure if I was helping, or bringing rain down on your plans.) ;)

Some early AM rambling:

A clone of the system is only for emergency, doesn't need to be as large, and only updated "as needed" it is more important that it just simply have the latest working system (such as 10.4.2) in order to fall back or use for repairs. The clone should go to B or C volume, not the faster area.

Sort of same with backing up /Users, you want /Users to be on the outer half of the drive (or whatever makes sense leaving 50% free and room for temp files stored in ~/Library/.

FW400 is awful and slow and not suitable for anything other than backup or an emergency boot drive. We see 35MB/sec writes at best in tests. Also requires one channel per drive, not a shared bus, and wouldn't really outperform a native internal ATA drive.

FW800 is better, and the Oxford 912 bridge has built-in RAID support, as LaCie (but that can be another problem) and the 2nd drive only offers 25-50% boost over a single drive.

That was why I looked for the 16MB cache 300GB boot drive, use the boot drive for PS scratch which would offer more like 60MB/sec.

The ATA/66 (ATA-4) bus is about 4% slower than the ATA/100 (ATA-6) bus. And with 160GB drive w/ 8MB cache I get ~55 on the one and 58MB/sec on the other. But that is part of why RAIDs across the two inevitable have problem.

I wonder if you could use two serial channels/drives for scratch maybe? Ideal would be two 10K Raptors which should do you well for years and provide ~135MB/sec. The G4 MDD maxes out at ~220MB/sec total and it takes a G5 w/ PCI-X to get beyond that limit.

Do you keep the 1.2TB online at all times? as needed? It doesn't look like a RAID there. Each pair could actually be hot swap drive bays. Also, keep 20% of the space free on those drives or you could exceed what can be stored safely. As well as performance drops off as it goes beyond 65%.
Three 500GB drives would handle your storage needs. But you know your own data and how best to maintain it. I go for three data sets, one live and two backups, so one set is safe and off-line at all times.

09-11-2005, 09:44 AM
Dear TZ,

It is all starting to make sense now.
Thanx for providing such valuable feedback.

Yes, I "could" steal one pair from the Burly tower to make a RAID 0 Swap. Would having the PS swap area go through the controller affect reading/writing to the other drives on the tower? If not, then that would suit me just fine. Guess there is no need for hotswap housings for those two RAID 0 babies, huh?

You are correct about the use of hotswap for manual archiving -- plan is to keep the archives offline (in a fire safe perhaps?) when not being backed up. Just going to have to be disciplined about it and not let it get too far behind.

Actually, I'm considering spending a few more dollars and for the rack mount hotswap Burly as my UPS is also rack-mount. I like the idea of keeping those drives as cool as possible.

One last question: I've read elsewhere (but not here) that some people are putting the OS swap area on a dedicated drive -- thoughts about that?


09-11-2005, 10:43 AM
Glad it has been of use.

Pushing the RAID to external SATA for your Photoshop scratch should help your system performance and lift some of the sluggishness, too. Limited by the type and performance of the drives you use. When you are rendering in Photoshop, you probably aren't doing concurrent I/O to the other drives. Now, if you were transferring files out to your Burly, or between SATA drives, yes, there is only so much bandwidth and traffic possible (220MB/sec on G4).

I think there are some PS test files and benchmark charts, but those were probably using Raptors and 15K SCSI, not "plain olde 7.2K drives" though even there, 250/300GB 16MB cache would be preferred. In the past, people had to turn to at least four or eight 15K SCSI drives to compensate for limited memory and slower systems. You could come close to memory speed/performance if you could get as close as possible to 300MB/sec.

OS Swap:

Yes, you might gain something if you had yet another 1-2 drives you could dedicate the outer partition for, and dedicate one channel of a SCSI controller. Normally, No. :D

What I do that helps a bit, is before installing the OS or cloning it to a drive, is to put a nice large 4GB file at the front of the drive. Afterall, the boot drive should be the fastest drive possible to begin with. Along with moving /Users off the boot drive, so the system can concentrate and not be distracted by other tasks.

I have no idea how many swap files you are creating and generating. And even with 2GB memory, Photoshop is not my forte as to what it does or what Tiger will do. PS has its own logic about what it does and when it uses memory or scratch space. Or when preparing pages for print.

With CS2 and Tiger, the system tries to cache as much as possible for Photoshop. And Photoshop uses that scratch when it runs out of memory. Which in your case, is often.

On a server, or on some operating systems, you would move virtual memory to the front of multiple disk drives or have one drive dedicated to VM (varies by OS).

I rarely see more than three swap files, and 15K boot drive isn't bothered by that.

I would love to see a Raptor with 16MB cache, or Maxtor DM10/MLIII with same, as boot drive, if not 15K II Atlas drive. A pair of 36GB Raptors in RAID0 for swap would be an interesting experiment. Even a single drive. Which leads back to ultimate boot drive and whether 15K SCSI or 10K Raptor, or 300GB w/ 16MB cache. Disk drives that you can keep throwing a work load on, and watch it perform. I prefer the idea of using many individual drives for different tasks, a result of using small fast SCSI drives and my background.

Right now is a good, stable moment in disk drive technology, I think. Mature fast SCSI drives, SATA is now two years old and beginning to 'mature' - not an over-night sensation. Even video cards can take months or a year to see drivers improve and deliver on their potential.

In some ways, Mac OS X boot volume is more like a server than a desktop OS (build on BSD, NeXT). When the G5 came out with internal room for two drives, and Apple's lack of support for native or internal SCSI left me... flabbergasted. Stuck dumb. (I look at IBM's IntelliStation POWER series as the "ideal" in workstation design, though.)

But now you are getting into tweaking a system to get the most, out of the wind and sails, so to speak, so you can wring more performance, or point higher into the wind.

09-11-2005, 06:28 PM
After re-reading everything, I just had an epiphany.

Since my backup drives don't need to be fast, I can re-use all my existing drives for backup purposes. Ideal for this is the Wiebetech ComboDock docking device, which allows me to hook up a bare IDE drive whenever I need an archival backup. I can treat /user the same way by using a bare 250Gb IDE drive.

Now, if instead of a Burly 8-drive tower, I got a Burly 4-drive tower (non-hotswap) and used the Tempo-X 4x4 SATA host card, then my four internal drives can be SATA and my four external drives can also be SATA.

36+36 Raptor RAID 0 swap drive
78Gb Raptor OS boot drive
250Gb Hitachi /user

(4) 300Gb Seagate in a Burly 4-drive SATA case

FIREWIRE 400 (Backup):
- Wiebetech Combo Card --> (4) 250Gb IDE drives
- 120Gb iTunes music files
- 200Gb OS backup

- USB2 200Gb IDE backup

The above puts all of my existing IDE drives to good use (mostly for backup), and keeps the new hardware costs down to approx $1581. I will have 1.2Tb SATA storage and 1Tb backup (for now)

I assume the Sonnet card is up to the task of efficiently handling all 8 SATA drives?


09-11-2005, 07:28 PM
Like this one. (http://www.macgurus.com/productpages/sata/tsata-x44a.php) :D Randy

09-11-2005, 09:14 PM
Since my backup drives don't need to be fast, I can re-use all my existing drives for backup purposes. Ideal for this is the Wiebetech ComboDock docking device, which allows me to hook up a bare IDE drive whenever I need an archival backup.

Funny, I was going to suggest that. We have a couple DriveDocks at work, and use them for cloning all the time...never a problem.

I like the idea of getting your backup out of the box. MDDs can be warm, so if you can get down to one drive in each bay, that's a plus. I see you have a good plan that uses all four bays, which should be OK, but two is nice IMHO. I don't play with RAID 0, but it will be interesting to see how much better performance you get than a single internal drive. Worth benching to see the specs both ways.

And, keeping your B/U on a shelf or better yet in that fire proof safe gives you more protection from all sorts of things, including lightning strikes and brown outs. Viruses too...if there ever is one for OS X.

09-12-2005, 06:48 AM
And where, in any, would Photoshop's scratch disk be?

I'm not sure how valuable it will be to dedicate two drives to swap and not use a scratch RAID for Photoshop on a G4.

Use the small Raptors for both swap and scratch? Use SoftRAID to partition the RAID and have a small 4-8GB swap space, and the rest as scratch???

A question of priorities or choices.

09-12-2005, 08:28 AM
ooops my bad. I wasn't clear.

The RAID0 "swap" is supposed to be the PS scratch disk.
Would two RAID 0 Raptor 36's be only marginally faster than one Raptor 74? If so, then I might go with one 74 for now to keep the heat down inside.


09-12-2005, 08:44 AM
Drive Performance Comparison Raptor (http://www.storagereview.com/php/benchmark/compare_rtg_2001.php?typeID=10&testbedID=3&osID=4&raidconfigID=1&numDrives=1&devID_0=267&devID_1=249&devCnt=2)

"Marginal" in there is a good deal of difference.

When WD came out with the 74GB model, only minor changes were made to their early small "beta" 36GB Raptor.

Raptor 74GB 70MB/sec vs. 100MB/sec for pair 36GB units in RAID.

I would consider getting two 74GB units. See what you can do, play around at first with them as RAID, boot from RAID, scratch, run some tests and benchmarks during the first week while letting them break in and loosen up.

As for heat, the Raptor heat and noise is very conservative. Check out the numbers in the reviews. And www.StorageReview.com is a good way to get to know drives. There are also links to reviews and such in our own Storage Reference if you haven't taken time to wade through (most of the info on Raptor is in one section though).

09-12-2005, 11:04 AM
So I just placed my order with MacGurus for a Burly 4-drive hotswap and Tempo SATA 4x4 card. SATA drives from NewEgg.com as well as TigerDirect who had a special on Raptor 74's: two for $409.

Looks like I have a long weekend in front of me...

Thanx everyone for the feedback. I'll let you know how it goes. Besides Xbench, what other before/after benchmarks should I be running?


09-12-2005, 11:07 AM
Found PshopTest on this site (some of the links are broken).

09-12-2005, 11:21 AM
Which links? I try, but Photoshop stuff is mostly out of my hands. I try to just keep the Troubleshooting Guide and associated links working.

I avoid Newegg and specials (OEM, older models very often). For good prices, I've come to rely on www.Zipzoomfly.com where a pair of Raptors is $360 or less.

Speedtools QuickBench and ZoneBench are good

09-12-2005, 12:49 PM
well, there you have me. zipzoomfly definitiely has better prices by far. Ah well, too late for me as I've already ordered everything.

Next time...


09-12-2005, 01:15 PM
Ah, well, maybe you didn't check out post message #3?

09-12-2005, 02:11 PM
I see at various PC Box sites hard drive coolers of various ilks. Looks like none of them would work in a Mac since they all assume 5 1/4 drive bays.

Has anyone added additional fans/cooling to the insides of a MDD?


09-12-2005, 03:37 PM
Yes. Most everyone here has, eventually.

At first I thought you meant in our Burly, and most users had to use those in the past when drives were even hotter (but slower).

The MDD - my MDD Reference has a lot of links to articles and how to better cool an MDD. And some members have done extensive "overhauls" of their case to add more cooling, better fans, etc. However, the MDD can take a full compliment of drives, PCI cards, and RAM, done right, and stay within safe temperature limits.

Be sure to keep your eye on cpu and drives with a utility like Temperature Monitor.

Fitting a drive cooler usually means leaving only one drive in each drive cage though.

Another site with case mods and cooling articles and photos (and links to same in above FAQ reference) is www.xlr8yourmac.com

I've got a 10K and 15K drive in the ATA/66 cage. I can put a 3rd in the ATA/100 cage, but by leaving it empty it keeps cpu temp down around 34C versus slightly higher 36-39C. Still well below accepted temps.