Hello Mutumba, in order:

1. Open the bottom and have a look. Here is a nice video
2. Any SSD drive will work
3. It doesn't any SSD will work
4. Intel is very very good, price wise OCZ has great performance

Opening your computer wont void your warranty unless in the process of replacing or fixing you damage something. In which case it will only be temporally disabled until the system is working again. So voiding is really difficult to accomplish.

Thank you

Dell advertise that the M18x R2 with 3 x 6Gb/s ssd's in a raid array. From what I have read and also investigated in my own M18x R2 is that the middle bay or interposter is a SATA II connection.

Wouldn't this mean even though top bay (0) and bottom bay (1) are SATA III @ 6 Gb/s the raid array would only work at 3 Gb/s SATA II speeds or am I missing something here? I am just trying to determine which way to go and what size SSD to choose ie 3 x 7mm SSD's or 2 x 9.5mm SSD's + 1 x 7mm 500 to 750 GB HDD or 1 7mm SSD + 2 x 9.5mm 500 to 750 HDD or or or........I have read so much information about this, and much of it conflicting, that my brain has become addled.

 I have seen pictures with an M18x R2 with 3 x 9.5 drives installed, another with 2 x 9.5 HDD's and a 7mm SDD but the more I read the more confused I get. Does anyone have a definitive answer as to what can actually physically fit and 6Gb/s or 3 Gb/s outcome for configuration without posting the standard link to the picture of the interposter connection in the manual.

PS Currently have installed :-

Hitachi 500 Gb Sata II 3 Gb/s Model HTS 727550A9E364 in Top Bay (0)

Hitachi 500 Gb Sata II 3 Gb/s Model HTS 727550A9E364 in Bottom Bay (1)

mSata 64Gb

 Thanks

OCZ are having many issues at the moment with quality control (no clear sign if they have sorted yet), which leaves Intel and Samsung which are both rock solid, the samsung has shown its better with uncompressable data tho, altho its write speed is marginally slower, its iops is higher, I'd go with the Samsung 830 myself.

Intel (in the uk at least) are offering cashback which puts their price point way down, which maybe a factor.  

Good to know Dell ditched the Seagate Trash and moved to Hitachi :)

Mutumba,

SATA 3.0 (6Gb/s) x2 (HDD0, HDD1)

SATA 2.0 (3Gb/s) x1 (HDD2)

mSATA SATA 2.0 x1 (3Gb/s)

Three 7mm on Primary HDD-0 sata3 6Gbs, Secondary HDD-1 sata3 6Gbs, Tertiary HDD-2 sata2 3Gbs

Thanks Chris, but could you expand & explain in laymans terms

Should I take this to the hard drive forum?