Maximum PC

Is there any benefit plugging a SATA2 SSD into a SATA3 port? Will plugging it into the SATA3 port give me the maximum SATA2 speed of the drive or will the speed be the same as if I plugged the drive into a SATA2 port?

should be no difference at all, the drive cant use all of the bandwidth that is available on sata2 let alone on sata3.

Yeah no difference. If a you're in the market for a board there's a lot of deal breaks in terms of specifications and features they support, but SATA 3 just isn't one of them quite yet.

if you plug a sata 2 port into a sata 3 port you will probably get no extra speed at all,anyway why do wanna use a sata 2 device with a sata 3 port?

Maybe mechanical HDDs and older SSDs can't use all the bandwidth of SATA2, but even Indilinx Barefoot-based SSDs are bottlenecked by SATA2 on sequential transfers. Sandforce-based and Crucial SSDs are restricted even further.

Highly parallel SSDs like some FusionIO products or those with onboard RAID-0 like OCZ Revodrives require more bandwidth than even SATA3 can provide, so they're forced to use PCIe or HSDL.

After a quarter century of relative obscurity, SSD technology has exploded in the last five years or so (perhaps the watershed SSD was the first Memoright to surpass HDDs in performance) to the point that most motherboard makers were caught by surprise. They looked upon PCIe as "videocard slots" and you were lucky to get even two.

I ran into my first SSD bottleneck over two years ago when I found my array of four Vertex1 SSDs limited to 650MB/s by the ICH9R southbridge on my Maximus Formula. As a result, last year I sacrificed one of my videocards to free up a PCIe slot for my RevoX2 and this year I chose a Big Bang Marshal with its 8 16xPCIe slots for my new Sandybridge build.

Indeed the OP should see no difference but not because it can't use the bandwidth. It's because it's already bottlenecked by its own SATA2 internally.