PDA

View Full Version : Poor raptor performance?



speters1
09-25-2007, 07:03 AM
I just put in two Raptor 74gb 8mb Cache into my 8core mac. One in slot 2 and the other in 3. I striped them in raid 0 with SR 3.6.4, HFS+, no journaling, optimized for workstation, with stripe unit siaze of 128kb. The revision number on drive 2: 31.08F31. The revision number on drive 3: 33.08F33.

I used quickbench 2.1 to test the drives. Extended test, 20-100mb.

-100mb: read:53 write: 157

Then I tested the individual drives with the same settings:

-100mb: read: 38 write: 69. Both drives where close to the same

The drive that came with the computer is getting around:

-100mb: read: 72 write:76

Any thoughts?

TZ
09-25-2007, 07:30 AM
Always best to have identical models. Why are you using the older units that had TCQ? rather than newer NCQ and 16MB cache? Raptors have always been slow on read.

I have two Raptors (16MB cache) and the newest (Mar '07 manuf date) outperforms the one from Aug '06 by a margin. In the 78-84MB/sec for writes and reads are 65MB/sec range. Stripping brings writes to 150MB range (same) but reads are 120 area.

Did you make sure to use default GUID? I think you have to in Disk Utility but not sure about SR 3.6.4.

the 750GB WD RE2/SE16 can out-perform Raptor in many settings (Barefeats).

Lately I've noticed that you don't necessarily need or want 128K stripe size.

QuickBench and ZoneBench should be updated to current version.

However, even with all of the above, the read score doesn't make a lot of sense.

speters1
09-25-2007, 11:12 PM
I was just trying to get some milage out of an old raptor. I already had one raptor that had the 8mb cache so I figured I would pick up another one to use in a striped raid 0 for my third computers scratch drive. I did not realize that there was a difference even between the 8mb cache drives. I did try and use both apple disk utility and sofraid to format the drive. When I used the disk utility I just used the default which I believe is "Apple partition map". As far as the RE16, are the 500mb versions as fast as the 750?

speters1
09-26-2007, 03:51 AM
As far as photoshop scratch disc is concerned wich is most important, read or write?

Boots
09-26-2007, 07:09 AM
I don't really know the answer to that in a definite way- but think about it:

if you're doing heavy scratch reading/writing 'cause you've used up the RAM, then I'd think the reading speed of the drive becomes more important because the scratch data is being used much more directly to execute a change to the image...but it's almost a 'which came first- the chicken or egg' scenario because if you're working fast, you may be held up waiting for new scratch data to be written in order to complete something you've just executed...

I think it would be nice if we had more control over the behavior of the VM buffering plugin-

meaning, it would be nice to be able to set an upper limit on how much RAM is used to buffer scratch data. I think this would come in handy working with the bigger image files and/or multiple applications open scenarios; one could stave off start-up disk swapfile paging that might otherwise occur by capping scratch data buffering well below the amount of installed RAM- then make up for less available RAM to buffer scratch data by relying instead on a really fast scratch disk (4 x 10/15k stripe) kicking in "early" so-to-speak....

TZ
09-26-2007, 08:06 AM
G5s use the older APL format. But only SoftRAID would let you specify something else (default for Intel is GUID)

WD RE2 750GB is available
Next: 2007 74GB Raptor 16MB cache
Next would be the 150 (which costs more like 750GB)
500GB RE2 @ $140 ea would let you build an okay scratch.
I think you can find the 74GB 16MB cache for about $150.

I'd say those old Raptors would be a nice small emergency boot drive. I don't think WD sells them so they could have been over stock, OEM or EOL. OWC doesn't seem to know what they have (wrong cache size for model name).

If you have an XP setup there, maybe you can run WD LifeGuard and see if you can update their firmware. I know that use to get discussed on StorageReview and what the various models and firmware changes were about.


Links to benchmarks and reviews for WD drives can be found in FAQ for WD.