Why such poor benchmarks with three X25M RAID0 on Adaptec 5405?

[idata]

I have three 80 GB X25-m (G2) on an Adaptec 5405. The partition is aligned. Here's what I get on AS SSD Benchmark:

238 MB/ SEC reads are not what I expected. I expected about 600 MB/ SEC. Write speed is mediocre. I've got the latest Win64 drivers from Adaptec installed. 5405 firmware is V5.2-0 16507. I have read and write-back cache enabled, I have a battery-backup for the Adaptec 5405. This is not worth all the money this setup cost me. The drives are new, they cost about $800 total and the controller was $225 on eBay.

Using my X58 motherboard, here are the results from AS SSD Benchmark using these three X25M (G2) drives in Raid0 off the ICH10:

Read performance looks great, due to cache. Write performance is awful.

WHERE'S THE BLISTERING SPEED THAT INTEL PROMISES?

If I'm doing something wrong, someone please let me know.

[idata]

Adaptec tech support pointed out that I had mistakenly set up my three X25-M drives as a SPANNED PARTITION and not RAID0! I GOOFED! Changing over to RAID0 and copying the backed-up drive image back onto the array did the trick!