PCIe SATA controller cards: Performance?

[Synomenon]

So I got one of the new Gigabyte Sandy Bridge boards. It has two SATA III ports and the rest are SATA II. Problem is, I have three hard drives and an optical drive.

I do have a free PCIe 4x slot. Do the SATA ports on PCIe SATA cards have slower / lower performance than the SATA ports built right into the motherboard?

I'm considering purchasing this card:
http://www.asus.com/product.aspx?P_ID=lGYmelQ8mJvPtYTv

 

[mxnerd]

According to spec, the Intel 160GB G2 read speed = 250 MB/s = 2 Gb/s, still slower than SATA II 3Gb/s.

You don't need to buy a controller to use all your drives.

===

One PCIe 2.0 lane = 500MB/s = 4Gb/s, can handle a RAID 0 setup of your Intel 160GB G2 drives (250MB x 2, if you have 2)

Bandwidth comparison
http://en.wikipedia.org/wiki/List_of_device_bit_rates

 

[Synomenon]

I just don't want to use the SATA II ports on my motherboard. Will this card work fine then for my drives? I plan on picking up two OCZ Vertex 2s as well.

 

[mxnerd]

No reason it won't. Each channel handles up to 6Gb/s =750MB/s according to ASUS.

OCZ Vertex 2s spec = 285MB/s

==============

Read the Newegg feedbacks before you jump in, seems quite a few people have difficulty making the controller work with Win7/x64.

 

[LiuKangBakinPie]

The onboard raid controller comes nowhere near a pci-e add in card. It way faster

 

[Zargon]

According to spec, the Intel 160GB G2 read speed = 250 MB/s = 2 Gb/s, still slower than SATA II 3Gb/s.

You don't need to buy a controller to use all your drives.

===

One PCIe 2.0 lane = 500MB/s = 4Gb/s, can handle a RAID 0 setup of your Intel 160GB G2 drives (250MB x 2, if you have 2)

Bandwidth comparison
http://en.wikipedia.org/wiki/List_of_device_bit_rates

there is a flaw in the sataII chipset on Sandy Bridge. thats why hes asking