Mac Pro with Western Digital VelociRaptor 600G ?

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Level 1

18 points

Mac Pro with Western Digital VelociRaptor 600G ?

Hello people,

Has anyone tried upgrading the HDDs in the Mac Pros with the new drive from WD

http://www.wdc.com/en/products/products.asp?driveid=821

From what i see, as the last model, this will probably not fit natively due to a lower pin arrangement that will not match the Mac Pro SATA slots with the factory HDD sleds. Am i wrong?

If you have this drive how does it compare?

Thanks

Mid 2010 Macbook Pro 15", 2,93 i7, 8GB RAM, 512GB SSD, Mac OS X (10.6.4), IPad 64 GB+3G,iPhone 3G 16 GB white OS 3.0, iPod Classic 160 GB, iPod Nano 8 GB

Posted on Oct 12, 2010 4:29 AM

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Answer 1

japamac

Level 7

24,400 points

Oct 12, 2010 5:02 AM in response to IamNehalem

Hi-

That drive of this following model is plug and play in the MP:
http://eshop.macsales.com/item/Western%20Digital/WD6000HLHX/

A pair of them in a striped RAID are as fast as the fastest SSD.

October 5th, 2010 -- For less that the price of one 256G SSD, you can buy two 10K 600G Velociraptor HDDs. If you stripe them (RAID 0), you get the same sustained transfer speed as the SSD. But, alas, the SSD can process 14 times as many small random transfer requests per second. Then again, considering you are getting 5 times the storage of the SSD and 3 times the transactions per second of the fastest 7K HDD, it's is an interesting option for a boot volume.

http://www.barefeats.com/quick.html

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Answer 2

IamNehalem Author

Level 1

18 points

Oct 12, 2010 5:03 AM in response to japamac

Oh great!

Now if we could get some feedback and why not maybe some quickbench results?

Agree those will be fast in RAID but not so fast than RAID SSDs. Would love to see 4xWD 600G in RAID 0 vs 4xSSD in RAID 0.

Question now: Due to the fact that the SATA interface in the Mac Pro is still SATA 2, how much will this bottleneck the SATA 3 ready WD?

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Answer 3

japamac

Level 7

24,400 points

Oct 12, 2010 5:12 AM in response to IamNehalem

how much will this bottleneck the SATA 3 ready WD?

About the same as SSDs.
The I/O bus is still the weakest link.
Also, the 6 Gbps VR is just a bit improved over the 3 Gbps VR:
http://www.maximumpc.com/article/news/firstlook_6gbs_sata_western_digital_velociraptor_600gbbenchmarked

Personally, I like the thought of great performance with capacity in the VRs.
SSDs are definitely improving, but still a young technology.

Imagine how the SSDs will perform after they have matured as the Raptors have...... 🙂

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Answer 4

IamNehalem Author

Level 1

18 points

Oct 12, 2010 5:12 AM in response to japamac

So the conclusion here would be to wait for a SATA 3 Mac Pro....along with USB 3 !? and maybe next gen Firewire...

wishful thinking 🙂

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Answer 5

japamac

Level 7

24,400 points

Oct 12, 2010 5:13 AM in response to japamac

Here are some RAID results:
http://www.storagereview.com/westerndigital_velociraptors_raid_ssdalternative

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Answer 6

japamac

Level 7

24,400 points

Oct 12, 2010 5:18 AM in response to IamNehalem

SATA 6Gbps (SATA rev 3) has yet to show its full potential.
As with any new technology, the best is saved for last! 😉

If history tells us anything, I wouldn't hold my breath waiting for the new technologies in the MP.
Eventually, but when will they be deemed as "ready" for the MP?

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Answer 7

IamNehalem Author

Level 1

18 points

Oct 12, 2010 5:29 AM in response to japamac

Thanks so much for your blazing fast reply and your info!

Now that things got more clear for me it seems that 4 x WDs 600 in RAID0 is best bang for the buck with 1 SSD as boot drive for almost 0 access time (in the free superdrive slot).

Very happy that WD made them Mac Pro ready, not having to buy additional sleds.

Cheers!

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Answer 8

japamac

Level 7

24,400 points

Oct 12, 2010 6:13 AM in response to IamNehalem

No worries! 🙂

4 x WDs 600 in RAID0 is best bang for the buck with 1 SSD as boot drive for almost 0 access time (in the free superdrive slot).

Gonna' go fast, eh?!? 😉

Very happy that WD made them Mac Pro ready, not having to buy additional sleds.

Plug and play as it should be.... easy!

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Answer 9

IamNehalem Author

Level 1

18 points

Oct 12, 2010 6:24 AM in response to japamac

Yes but now i was thinking that stripping 4 WDs would most certainly saturate the 3Gb/s bandwidth. From the links provided above, i've seen that stripping only 2 would result in a roughly 280MB read speed. Having said that let's assume that 4 in RAID would almost double the speed so that would mean roughly 550MB/s. Let's assume even less 450MB/s but that would still mean a lot more than the theoretical bus limit of 375MB/s (3Gb/s).

Hmmmm...

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Answer 10

The hatter

Level 9

60,990 points

Oct 12, 2010 6:37 AM in response to IamNehalem

Your numbers don't add up and don't take into account that while Apple says each drive has 300MB/sec (3Gb) actually they all share a common controller but which is more than 400MB/sec.

Three SSDs can saturate or show diminishing returns, yes. But they are hitting 550MB and above.

135MB/sec maximim per VR = 540MBsec. If you put the SSD on the same controller, then you do hit the ceiling... at some point, in some situations, where the system and 4 drive array are all at maximum IO and CONCURRENTLY.

So you bus limit is predicated on all four drives on the same bus/controller and leaves out the 750MB common controller.

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Answer 11

japamac

Level 7

24,400 points

Oct 12, 2010 6:41 AM in response to IamNehalem

When talking single drives, one looks at bandwidth per individual channel.
With internal RAID, you combine channels that lift the ceiling on the bandwidth.
All feed to a much faster pipeline.

Here are some tests comparing internal RAID vs external RAID with SSDs:
http://www.barefeats.com/hard132.html

As you can see, the combined throughput is greater than a single channel alone.

Message was edited by: japamac

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Answer 12

IamNehalem Author

Level 1

18 points

Oct 12, 2010 6:54 AM in response to The hatter

Why is my calculation incorrect?

I thought 375*8=3000 Mb/s or /1000= 3Gb/s. This was just a rough calculation of the controller speed because i didn't take into account only one thing, that is the fact i used a decimal (base ten) system instead of binary (base two) math.

In base 2 one 1GB/s is 1,024MB/s, or 1,073,741,824 (1024x1024x1024) bytes/s.

Considering the base 2 math that would meant he controller is limited to 3000/8/1024*1000=366,2 MB/s.

Estimated speed of 4 stripped WDs would most probably surpass that.

Please correct me if i'm wrong. I may be too tired...

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Answer 13

IamNehalem Author

Level 1

18 points

Oct 12, 2010 6:58 AM in response to japamac

So you're saying that i can assume a new stripped pipeline with a theoretical limit of 3Gb/s * 4 = 12Gb/s ?

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Answer 14

The hatter

Level 9

60,990 points

Oct 12, 2010 7:19 AM in response to IamNehalem

There is one SATA internal controller with about 750MB/sec or 600MB/sec shared by all four drive bays.

There is some overhead so that even 300MB/sec is 250MB in real data thruput.

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Answer 15

IamNehalem Author

Level 1

18 points

Oct 12, 2010 7:29 AM in response to The hatter

Aham... but can you please tell me where are those numbers coming from? (tech spec speaking).

So that means Apple is advertising their RAID card to improve security and performance with RAIDED HDDs since it has a broader controller than the one internally in the mobo?

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