Thank you for purchasing through links and ads on this site.
OWC / MacSales.com...
diglloyd Deal Finder...
Buy other stuff at Amazon.com...
Upgrade the memory of your 2018 Mac mini up to 64GB
Small Business Tax Write-Off?
Now is the time to purchase computer or photo gear for 2018 federal tax write-off. Consult with Lloyd.

Promise Pegasus J4 — SSD Speed (Compressible)

Last updated 2013-07-03 - Send Feedback
Related: SSD, storage, Thunderbolt

Tested on the 2.7 GHz MacBook Pro with Retina display, which has a Thunderbolt connector. This test is for compressible data.

Update: see issues.

Sustained transfer speed — compressible data

The Thunderbolt v1 bus speed effectively throttles peak performance to just under 900 MB/sec for reads. Observe that 2/3/4 drives striped all effectively perform the same for reads of compressible data.

Since read activity dominates most workflow scenarios, it is fair to say that even two OWC 6G SSDs in this Pegasus J4 will provide enviably robust performance.

Write speeds are lower, and this appears to be a Thunderbolt or Pegasus limitation, because write speeds on a native SATA 6Gbps connector approach 500MB/sec for a single SSD.

But none of that really matters: the speeds with even two SSDs are well beyond the ability of nearly every program to use the high speed in any meaningful way. Even Photoshop CS6 sees greatly diminished returns after ~600MB/sec.

For compressible data, the sweet spot for reads and writes is the triple-SSD configuration, which leaves that 4th bay free for a high capacity hard-drive utilized as a clone backup.

Tested with diglloydTools DiskTester using the fill-volume test.

RAID-0 stripes of 2/3/4 SSDs + single SSD
(Data from diglloydTools DiskTester data graphed from fill-volume test)
RAID-0 stripes of 2/3/4 SSDs + single SSD
(diglloydTools DiskTester data graphed from fill-volume test)
Deals Updated Daily at B&H Photo
View BEST Deals Right Now
B&H Deal ZoneDeals by Brand/Category/Savings
Deals expire in 12 hours unless noted. Certain deals may last longer.
$599 SAVE $200 = 25.0% Canon 17-40mm f/4 EF L USM in Lenses: DSLR
$520 SAVE $130 = 20.0% Canon 70-200mm f/4 EF L USM in Lenses: DSLR
$449 SAVE $100 = 18.0% DJI Goggles Racing Edition in Video: Drones
$299 SAVE $50 = 14.0% $149 FREE ITEMS DJI Spark Quadcopter (Sunrise Yellow) in Video: Drones
$50 SAVE $100 = 66.0% Lowepro DroneGuard CS 400 in Video: Drones
$2497 SAVE $300 = 10.0% $29 FREE ITEMS Nikon 70-200mm f/2.8 AF-S NIKKOR E FL ED VR in Lenses: DSLR
$898 SAVE $500 = 35.0% Sony a7 II Mirrorless in Cameras: Mirrorless
$898 SAVE $506 = 36.0% $19 FREE ITEMS Sony a7 II Mirrorless with Accessory Kit in Cameras: Mirrorless

diglloyd.com | Terms of Use | PRIVACY POLICY
Contact | About Lloyd Chambers | Consulting | Photo Tours
Mailing Lists | RSS Feeds | Twitter
Copyright © 2008-2017 diglloyd Inc, all rights reserved.
Display info: __RETINA_INFO_STATUS__