We've posted test results for SSDs in various configurations inside the Mac Pro and MacBook Pro, but, up until now, we haven't posted much about external eSATA host adapters and enclosures that are compatible with SSDs. We used three different eSATA host adapters to test two or more SSDs in RAID 0 sets.
I threw in some numbers for the fastest HDDs to give some perspective.
LEGEND of GRAPHS
Quad HDDs SeriTek = Four Hitachi 7K2000s in a SeriTek 2eEN4 enclosure connected to SeriTek 2ME4-E host adapter (each drive with its own dedicated port)
Quad SSDs SeriTek = Four OWC Mercury Extreme 200G SSDs in SeriTek 2eEN4 enclosure connected to SeriTek 2ME4-E host adapter (each drive with its own dedicated port)
Triple SSDs SerTek = Three OWC Mercury Extreme 200G SSDs in SeriTek 2eEN4 enclosure connected to SeriTek 2ME4-E host adapter (each drive with its own dedicated port)
Dual SSDs SeriTek = Two OWC Mercury Extreme 200G SSDs in SeriTek 2eEN4 enclosure connected to SeriTek 2ME4-E host adapter (each drive with its own dedicated port)
Dual SSDs MaxPower = Two OWC Mercury Extreme 200G SSDs in SeriTek 2eEN4 enclosure connected to NewerTech MAXPower 6G PCie eSATA RAID host adapter (each drive with its own dedicated port)
Dual SSDs internal = Two OWC Mercury Extreme 200G SSDs inside the Mac Pro drive bays
Dual HDDs internal = Two Seagate Barracuda 7200.12s inside the Mac Pro drive bays
Single SSD internal = Single OWC Mercury Extreme 200G SSD inside the Mac Pro drive bays
Single HDD internal = Single WD Caviar Black (WD2001FASS) mounted inside the Mac Pro drive bays
NOTE: Icy Docks were used to mount the SSDs inside the SerTek 2eEN4 enclosure and in the Mac Pro drive bays. QuickBench 4.0.4 was used to test large sequential and small random transfer speeds.
1. The internal Mac Pro configuration was significantly faster than external configurations we tried. It took three external SSDs to rival the large sequential speed of two internal SSDs. It took four external SSDs to equal the small random write speed of two internal SSDs.
2. We added sample HDDs for perspective. As you can see, single SSDs smoke single HDDs. Two internal SSDs (and three external SSDs) were as fast as four external HDDs.
3. Though the MAXPower is rated as 6Gbps, is only a one lane PCie card. The 3Gbps rated SeriTek is a four lane PCIe adapter. That's why it attained high transfer speeds when connected to the two SSDs. When we added three and then four SSDs, there the law of diminishing returns kicked in. On the other hand, the MAXPower does support RAID 5 and is a bargain.
I expect future 6Gbps SATA host adapters with 8 or 16 lanes will tap the full potential of SSDs. Four of SSDs should achieve 1000+MB/s when there are no PCIe bus bottlenecks. Of course, such a host adapter will be more costly. But if you can afford four or more SSDs, you can surely afford a host adapter that will squeeze out their full potential.
DELAY on PART TWO: MacBook Pro ExpressCard
Rather than throw all the data at you at once, I decided to hold back the results of running external SSDs on the MacBook Pro. We have delayed posting until Friday, June 4th so we can include fast 3.5" SATA drives externally and up to four SSDs eternally using a Port Multiplier enclosure. We want you to see all combinations of external SSDs and HDDs on the MacBook Pro Core i7 and C2D using the fastest dual port eSATA ExpressCard/34.
Meanwhile, here are a few insights to ponder:
1. The fastest MacBook Pro ExpressCard/34 SATA adapter tops out at 200MB/s even though SSD drives capable of 250+MB/s as a single drive and 500+MB/s as a dual drive RAID 0 set. That should give you a hint as to what you will see in the graphs. The only way to go faster than 200MB/s is to put the SSD internally -- or to put dual SSDs internally using the Optical Bay kits.
2. The 2009 MacBook Pro C2D (17") posted significantly faster WRITE speeds than the 2010 MacBook Pro Core i7 (17"). That hints that Apple is using different ExpressCard/34 electronics for the two models. Let the speculation begin.
3. The fastest notebook HDD (Seagate Momentus 7200.4) maxes at 100MB/s. If you need a faster HDD, there is always the fast 3.5" HDDs like the WD Black 2TB which measures transfer speeds at 140MB/s+. No matter what enclosure you use, they also max out at 200MB/s when two are more are in a RAID 0 set.