Well, clicking a thread for example will make a request to the MySQL database to retrieve the post data contained inside that thread. The more requests that happen per second, the slower the server will be. You could have a 4 x quad opteron setup with 16GB of RAM, but with a simple SATA drive, the 'wait' time of the HDD will pretty much render all the other hardware useless.
Something that should be analysed is the %wa that appears when you do a top command in Linux; if it is over 10% you will start to see slowness.
A SCSI drive spins faster than a normal IDE or SATA drive, decreasing access times and allowing for more mysql interaction per second. You should consult with your service provider about this, as they should be able to tell you if this is causing trouble during peak load times on your website.
Ahhhh, I gotcha. Totally makes sense then.
I guess I'm caught in a place where I NEED to upgrade b/c we are noticing definite server issues, but I'm also going to be at the very top of my budget once I do upgrade, without the additional $120 a month factored in for the SCSI. Oh, how I wish this whole process were easier... and cheaper.
I appreciate your help though. I'll go ahead and contact them in regards to the SATA vs SCSI issue to see if that's something that I need to heavily consider.
--------------- Added [DATE]1210708009[/DATE] at [TIME]1210708009[/TIME] ---------------
Update:
After googling and searching vbulletin.com like crazy, I decided to go with this:
# Dual CPU + Dual Core Opteron 2212 (4 cores total)
# 4GB RAM
# 4,800GB Premium Tier1 Bandwidth
# 160GB SATA Main Drive - Free Upgrade from 120GB
# 160GB SATA Backup Drive - Free Upgrade from 120GB
However, I am also currently educating myself a bit more on the SATA vs SCSI and will probably end up upgrading that, as well, eventually. For right now, I'll see if the basic upgrade will work for us for a while, then upgrade again if needed.