Some time ago I actually dug into this problem quite extensively and what I found was that under no or very little traffic times (no one actively shopping), ProductCart will consume between 20-40MB of its application pool.  Now when you start browsing the store you will have period spikes in resource usage which is Perfectly Normal and expected with any ecommerce application. Depending on the amount of traffic you have, you will see spikes definitely up to 100MB but more often than not you will see it peaking out at 150-180MB.  Occasionally you will get above 200MB.

 

Matt's suggestion of 250MB is right on the money.  I would say that 200MB should be the minimum for your site.   There are many indicators of when it is time to switch to a dedicated or VPS environment and pool usage is definitely one of them.  When I am evaluating my own customer site's performance, I start getting concerned when they are consistently spiking above 200MB. If I do see that, the first thing we do is take a look at the code and any modifications as a memory leak can cause high pool usage as well.  If all is good there, we may try tweaking the environment but in the end, it may come down to moving them into their own server. 

 

PLEASE NOTE:  I do not want readers of this post thinking this is a ProductCart problem because is absolutely IS NOT! I would give the same advice for ANY ecommerce application running on Windows.

 

Very important that you confirm with your host your site is set into a Dedicated Application Pool.  Then ask them if they can adjust that application pool's resource allocation to a higher value. 

 

To be honest many budget hosts are not willing to do this because they are not really set up for application hosting.  The whole goal of a budget host is quantity and not quality.  That in and of itself is not necessarily a bad thing but it certainly does not mesh with what you are trying to accomplish as a store owner.

 

Many of us on the board likely sound like a broken record in this regard but it is so vitally important you host your ProductCart site with a host that understands the software application.  If you had an oscommerce site, I would tell you to pick a host that specializes in that application. 

 

Hope this helps some.