Xandris wrote:
I am NOT exactly positive about this, but I dont think you can RAID 2 drives of different size. A 500GB and a 512GB drive will not be able to be used in RAID.
Sure you can, but with the caveat as mentioned by "IftiBashir":
You cannot RAID 2 different sized drives.
Well you can, but you will lose some space on the bigger drive, so the OS would treat both drives the same size (the size of the smallest drive).
That being said, I think the "The Apple 512GB SSD is actually 500.28GB", see "Special Report— Real World SSD Performance — Apple 500GB SSD (2010)" (
http://macperformanceguide.com/SSD-RealWorld-BeforeAfter-AppleToshiba512.html), which seems to be in line with what the poster ("patimages") was stating:
I have a Macbook pro core I7 - 15'' (2.66HZ - 500GB SSD drive)
As far as:
the newer SSD drives with the SandForce controllers have TRIM built into the firmware of the drive.
True, but OS X 10.6.4 does not support it, to my understanding. And, by way of example look at one of the top of the line OWC SSD, the "OWC Mercury Extreme Pro RE SSD 400GB SATA 3.0Gb/s Solid State Drive" (
http://eshop.macsales.com/item/Other%20World%20Computing/SSDMXRE400/), which states in the specs: "TRIM Support: Advanced TRIM Support in Windows 7"
I really enjoy reading through these posts because it makes me dig deeper and deeper into the "SSD craze". Of interest, I found "Measuring and Understanding True SSD Performance and Consistency ..." by Kent Smith, Sr. Dir. Product Marketing at SandForce. I could not open the PDF from their website, but was bale to access it via "quickview" (
http://docs.google.com/viewer?a=v&q=cache:Hehq-n7PDIUJ:www.sandforce.com/userfil es/file/downloads/FMS2010F2A-Measuring_and_Understanding_True_SSD_Performance_and_Consistency_Kent_Smith. pdf+trim&hl=en&gl=us&pid=bl&srcid=ADGEESgoPtzeNUKWJAMRAE-oCUqjX2NYt5jTqhggkiNiGo wwjSeLCeET7oFBwpDaCp3rXaXXxITf7JXUzDbVObafp-KnBn3h-QmGfMBfc2rzkM8FQDKJGJIN9v5pt_ nKVsWoXpFX6De&sig=AHIEtbSgZg0f74CypaRpGH11cgen1k-aRA). I think it gives some good insight to SSDs.
Then it allows one to have a better grasp of the OWC SSD specs (from link above).
Consistently Fast & Reliable
28% Enterprise class over-provisioning along with RAISE technology offers real-time redundancy and data protection against data loss from flash cell failure. The over-provisioning provides exclusive capacity for wear-leveling and cell replacement so you can enjoy years of reliable, high-data load operation without any performance compromise.
As a well as:
Capacity:
400GB* useable capacity
# Total Flash Memory Components - 512GB
# 112GB allocated to enterprise-class real-time data redundancy & error correction
*1GB = 1,000,000,000 bytes. Total accessible capacity varies depending upon operating environment (typically 5-10% less). The actual total capacity will depend on your own defined file settings/preferences.
And not to confuse the issue, but if you search around, it seems that SSD TRIM support does not work in a RAID and there is some question as to the performance of the garbage collection on SSDs set up in RAID-0.
But then, there is the "NewerTech Guardian MAXimus mini 400GB + 400GB 800GB total capacity" mentioned in previous post (
http://eshop.macsales.com/item/Newer%20Technology/GM8QMSSD800/) that can use two OWC Mercury Extreme Pro RE SSDs for RAID 1 or RAID 0. Given that the OWC Mercury Extreme Pro RE SSD uses "RAISE (Redundant Array of Independent Silicon Elements) protects the data on your drive similar to having a RAID setup" I am not sure what that actually translates to in setup / actual operating - RAID 0 with disks with RAISE? Sounds good, but don't know how it would play out in real use.
And just put this in perspective, as others have mentioned, the 500GB Seagate Momentus XT solid state hybrid drive (
http://www.seagate.com/www/en-us/products/laptops/laptop-hdd#tTabContentOverview) delivers speed at a fraction of the cost of an SSD. Take a look at their video +*"Compare solid state hybrid drives to SSD and HDD"*+. Although the end point is that their drive is slower than an SSD, for the cost it is a great deal. I cant disagree, but also have to admit that despite the problems / confusion circulating about the SSDs, seeing the video really just makes me want to try an SSD more.
