Hardware recommendations for MySQL

[Daryl Readman]

We currently have multiple MySQL servers holding tens of millions of records. Routinely, clients of the company upload tens of thousands of more records that are immediately compared to our databases for duplicates, deletes, and authentications and depending on the information content, they get moved around to other databases. These processes are extremely high volume and quite constant throughout all hours of the day. Over the years we managed to keep up with the latest architectures of MySQL and have refined our databases and query code to match the most efficient designs. So software is not a problem for our developers. The problem is, every time the server load gets too high, the company owners are pretty much only willing to buy an extra stick of ram, or an addition cheap ass $300 machine to add to the network. We're trying to convince them that a top of the line server would greatly handle all our databasing needs, but the $4000-$5000 price tag confuses them. I need definitive proof of performance gains vs state of the art hardware, and what advanced hardware components are required and which are not.
I need to prove this without going out to buy one. I've already looked at some of the whitepapers on benchmark performances, but I need to see a document that explains the benefits of each hardware peripheral towards running MySQL.

The following is the ideal machine that we're interested in.

Intel Dual Xeon 3gz (800FSB) 2 MB Cache
2GB DDR2 (400mhz)
RAID5 72GB 10k Ultra320 SCSI
Dual 1GB Ethernet

Can anyone explain how greatly MySQL implements on such a machine, or is it just overkill? Does anyone know of a technical paper / document that explains how MySQL benefits from Dual Processors, 2GB RAM, the RAID5 cluster of hard drives, and the gigabyte ethernet? The benchmark papers seems to only show the performance differences between other database solutions, and not against hardware directly.

Any opinion or help would be greatly appreciated.