Useable memory setting?

[jebo_4jc]

So I hadn't touched my boxen for a while.
I built a new MCE htpc for my in-laws with a sempron 64 2500+ and 512mb of RAM
(Those S64's are awesome little chips BTW. Run cold as ice and plenty of o/c headroom)
Of course, before I put it in their home theater cabinet, I pushed it up from 1.6ghz or whatever the normal speed is to about 1.8 or 1.9, and installed F @ H on it
I was setting up the console version and....what's this....we can change memory settings now?
I was pleasantly surprised.
I don't want to see this thing's RAM get sucked down by FAH, since I'm sure the MCE interface needs it's fair share of RAM.
Since it only has 512MB of RAM I set the useable RAM size to 300mb or so (I can't exactly remember).
Question is, what do you think the optimal setting is for this setup?

 

[unhappy_mage]

300 is probably a reasonable setting. That'll let it use big WU but not bog it down too much.

Lovely little simile there, btw...

 

[jebo_4jc]

Lovely little simile there, btw...

It's valid.
But I changed it anyway.

I'll leave it at 300mb. thanks.

 

[SpoogeMonkey]

That's more than plenty. I think the biggest wu (600 pts) uses just over 100mb (118k or so)