UDMA6 can help for reading, but as for write speeds they are the bottlenexk of MLC based SSD.
write speeds can never be as fast as the samsung SLC, as SLC is hard to beat, and the memory chips cost alot more than MLC chips. The only way MLC NAND found in modern SSD like runcore and photofast is by using large buffer RAM, hence why photofast V4 has 64Mb cache to assist.
Newer SATA based MLC SSDs have improved overall performance by running more memory chips in parallel, is essence a form of stripe RAID.
micropc hardware: sony ux17gp with 390N mainboard with Anh u7700 upgrade core2duo 1.33ghz 1024mb (now upgraded to 64gb SLC SSD Samsung), Intel 4965 agn wireless, upgrade addon 3rd mini aerial, UX37GBN blue housing incorporating improved keyboard
OS: Linux Ubuntu 10.04 lucid & now 12.04 Precise Pangolin!
sony 380N stock 1.33ghz, 1gb ram, and 40gb rotational drive OS: windows ultimate
light slim notebook: toshiba r200 1.3ghz 1.2gb ram 64gb photofast v1 ssd oS: linux ubuntu 7.04 feisty fawn