The drive will run at the slowest interface speed...so it'll run at whatever spec the EIDE spec is...
I'm not a PC/Server guy, but I typically avoid at interface conversion if at all possible. Anytime a conversion happens, things are slower then they could be. Also, in this case, it is real low level stuff so it could be low quality as well.
I could be all wrong, so what for confirmation from someone who knows hardware pretty well. IMHO, if you have SATA on an XPS...get a SATA drive.
My '03 Sold.