Has anyone tried the Solid-State drives with EIAS?  These are hard drives which use RAM instead of disks to read/store info.  I was considering getting an array of 32GB drives, one drive per processor on a MP machine.  Has anyone tried this?

Yon

*edit* the cheapest route I see is the Ritek 2.5 disk with a 2.5 to 3.5 converter… it’s about $300, which would be well worth it if it’s reeeaaaly fast

Hi Yon-
There are 2 kinds of Solid state drives.
The SSD drives are flash memory based (just like digital cameras, etc.) and this is what is being used in the Macbook Air. These have very fast random write speeds, but are not too much better than a standard hard drive for large file transfers.

The more exotic kind is the true RAM hard drive. This type of drive will lose all of it’s data if it loses power. Usually these are a PCI add-in card.
These are hard to find and are the most expensive, but their data rates are outrageous. Faster than any hard drive or RAID available. These may cost many thousands of dollars, and I have no idea if there is one that is Mac-compatible.

The fastest hard drive today is the Velociraptor.
It is about 2.5 times faster than the stock Seagates in the current Mac Pro.
Unfortunatly these do not have a standard SATA connector arrangement- so they will not just plug-in to the Mac-Pro’s drive bays.

Otherworld Computing had a note online that they were expecting a new batch of velociraptors compatible with the MacPro soon.
http://eshop.macsales.com/

Whether a faster hard drive will help with rendering time is variable with the project. Under certain circumstances I have seen up to 180MB/sec transfer with 8 slaves distributed across 4 drives (I am using the cheapest SATA drives I could find- about $50 each). Under other circumstances Heavy RT and GI calculations take much longer than just the data transfer- most of the time the drives are doing nothing.

You can monitor this while you are rendering in Activity Monitor under the Disk Usage tab to see how much data you are really pushing, and whether you are saturating your current bandwidth or not.

Good luck- and let us know what you find out in your research.

Dave

*edit*
The Velociraptors top out at about 120MB/second sequential transfer speed. About twice as fast as the stated max for the Ritek drive you mentioned
http://www.barefeats.com/hard103.html

Mounting in a MacPro
http://www.barefeats.com/hard106.html

Dave,
Unfortunately, I’m finding much of what you are finding.  I’m seeing some articles which suggest that the write times on the drives I suggested are about the same as a standard hard drive, but the read times are very fast (good for large textures).  I’ve also found 3.5 drive boxes that hold standard RAM.  These of course wipe out all the data on shut down, but for slaves seem like they could be ideal.  A script could copy the slave folders to the RAM disks on start up.

You do have a very good point however, if the drives are only used a bit during a rendering, does it matter?  So this begs the question, which is would be more important to a set-up; built in RAM (most likely 2GB per processor), faster processor chips (2.8 vs 3 vs 3.2 on a Mac), and or hard drive speeds.  My sense has been that the harddrive has been the bottle neck here, assuming you don’t run out of ram.  Do you have a sense what the best set up might be?  I’m about to build a new system.

Yon

Actually, there may be a quick way to test the speed difference a RAM drive could add.  I recall for OS 9 there was a utility which could take part of your RAM and make it a partition disk.  I’m not sure if OS X has that too, but it would be interesting to see if a slave on a RAM disk would benefit the time.  I’ll do a bit of digging.

....

Dave,

I forgot to thank you for the very in-depth reply.  It was very kind of you to put in the thought, and the links.

Yon

Hi Yon-
I spoken with the developers about RAM disks, etc.
I have done a few tests that show some slight improvement in speed using a RAM disk, but only 10-15%.

I have also tried overclocking my 2.8 MacPro with the utility from MacWorld UK.
This works, I got it up to 3.1 Ghz from2.8 but I had some minor issues with my 8800 Video Card- So I went back to the default settings for now. I saw a 14% improvement in rendering speed with the faster processor setting. Good, but not worth system instability, however minor.

Apple charges a ridiculous premium for the faster 3.2 Ghz processors. Unless you have a machine dedicated to rendering 24 hours a day, every day, it is hard to justify the extra $1600 for a 14% performance improvement.

Here’s my recommended configuration for a Mac Pro that will be used for modeling, rendering, and post....
MacPro 8 core (4 cores x 2) 2.8 Ghz.
nVidia GeForce 8800GT (very noticible performance over the stock radeon card)
14GB RAM (add six 2GB modules to the included 2 GB)
Add 2 80GB Seagate Barracuda Drives for Slave Drives
Add one 750GB Drive (and partition it) for one slave drive and one Time Machine Backup.

I would recommend checking with EITG Sales for the MacPro- They have given me some good deals
For the RAM and Hard Drives try Other World Computing- The 80GB drives are under $50 each. And they have the best deals on RAM- and excellent customer service if you have any problems.

I generally run 6 or 7 slaves with 1.5Gb to 2GB ram each.
This normally leaves a bit of RAM and a CPU or two for me to continue working while the slaves are rendering.

Good Luck!

Dave

I just got my new MacPro and want to eventually install additional drives to run slaves. I was able to install 3 older 300Gb drives in the 3 open bays and I set them up as striped raid. I haven’t done any rendering yet but it seems significantly faster. Would it make a difference (to Camera) if the drives were completely separate volumes or striped raid?

thanks
brian

bwcc - 16 August 2008 06:20 PM

I just got my new MacPro and want to eventually install additional drives to run slaves. I was able to install 3 older 300Gb drives in the 3 open bays and I set them up as striped raid. I haven’t done any rendering yet but it seems significantly faster. Would it make a difference (to Camera) if the drives were completely separate volumes or striped raid?

thanks
brian

Yes the RAID will be faster than a single drive even for rendering IF AND ONLY IF file I/O is the bottleneck. This should also help Photoshop with scratch disk etc.

For rendering to multiple slaves using Renderama IN THEORY 4 separate drives should be a bit faster. Because there will be fewer file requests per drive. On a single RAID volume you will still have up to 8 slaves competing for file read/write priority.

IN PRACTICE, however, I would expect that a multi-drive RAID would be just fine for Rama Rendering due to the increased bandwidth.

Again- do some test renderings via Renderama and monitor the throughput in the Disk Usage Tab.
If you have constant data through-put in excess of 20MB / sec multiple HDs or a RAID setup should help your render speed. If you only have a short spike of data transfer at the start and end of the rendering process, multiple drives will not help much as the rendering process is bound more to the CPU speed rather than Disk Speed.

If you want to see a lot of data transfer- just create a PRJ with an Illuminator, with lots of light “samples” in the illuminator, and buffer shadows. This should create a large data transfer situation for testing.

I would be interested in seeing the maximum through put with RAID and comparing that to a multiple drive setup.

Brian,
My current set up has three drives, and it does run faster when the slaves are on different drives.  Ian also has suggested that multiple drives is the way to go, and unless you have a very fast connection to an external, internal is the way to go. The slave on my external drive is slower.

OWC sells a RAID controller which is supposed to perform much better than Apples, and it’s cheaper.  We’ve done raid set ups in the past (early 2000’s) and at the time it was not worth the expense for the difference.  Make sure the drives are right for the setup, as I’ve read that can be an issue.

Dave,
Thanks for that over-clocking info.  I agree that 15% isn’t worth the money or worry.  It’s interesting to hear your experiences though.  I’ve read that the Macs perform best with all the slots filled, next best with just 4 filled.  It am not recalling the exact percent, but I seem to recall it was noticeable.  Thanks for suggesting a set up.  I think it is exactly the one I want.

I was planning on asking Phil what their price is, and I’ve also had very good experiences with OWC over the years.

Yon

I ran some tests with a utility call ramBunctious, which creates a RAM disk from system RAM.  I’m not sure how it deals with the allocation, but running a rendering which takes 20 minutes on a normal hard drive slave took 19 minutes on the RAM disk.  This bears out Dave’s point about disk usage.  Unless the project calls the disk continuously during the rendering, there is little to gain by investing in very costly RAM drives.

Yon