For a desktop, do we get a 2.5" or 3.5" SSD? I ask this because most of the SSD I have seen is 2.5"

u will void the warranty

Are you sure?
Last I know, Asus allows you to replace any replaceable parts (like RAM, HDD, DVD/blu-ray drives) without voiding the warranty.

Or have they changed their warranty policy?

I know Dell doesn't allow it though.

If dont have any sticker or what so ever mark that will show u had opened the bottom panel then it is safe for u to change HDD to SSD

and as for acer . They usually have acer sticker on a screw at bottom of ur laptop

just a simple question here. i saw a corsair model ssd saying that it specs are read 500mb/s and write 500mb/s and then there's a part saying 6gb/s sata3 does it mean if i connect the ssd using sata3 cable to a sata 3 port on my mobo it will transfer till 6gb per second? thanks for answering in advance =D

I just got Intel 330 120GB and I manage to hit 200MB/s read and 160MB/s write based on the benchmark from the tool provided at 1st page. Is there something I miss out? I'm on SATA2 mobo, or it's my chipset/mobo controller problem? Was expecting around 250M/s read =(

actually 1 byte = 8 bits
so 1Gb/s should be 125MB/s

but also depends u count 1K as 1024 or 1000

but i not sure why wikipedia also list 6Gbps = 600Mbps

Mathematically and thereotically, yes 6Gbps (SATA3) is 750 MB/s.
However SATA ports are not designed to take full advantage of the speeds available to it.

This is due to protocol overhead, where 8 bits = 1 byte.

Simply put, the maximum speeds of a SATA port are as follows -

SATA 3 = ~600MB/s
SATA 2 = ~300MB/s
SATA 1 = ~150MB/s

'~' denote the fact that you won't reach the maximum available speed on the port, but more or less even if your SSD has 600MB read or write speed.

Hope that clears everything up.