Shipping estimates slow for larger orders

[asudol]

Issue: Larger orders cause my shipping estimator and on checkout to perform very slowly and time out. Other than 'flat rate' type options, none of my shipping modules that actually query rates will finish. They work perfect for smaller orders.

Basic information: 1.3.9h, site has been running since March, same config, no major changes. Site hosted at justhost. Using Canada Post shipping module and WayToShip module.

Smaller orders (20-30 items) function fine. Both shipping modules return proper responses. But once the qty of items goes up to 50+, the modules choke and never return an estimate.
WayToShip has confirmed that they don't even get the request on the large orders.. which tends to point to the cart and not the module.

Although we use dimensional support on both modules, the size does not matter. We've tried with our larger products (6"x4"x4") and with tiny products (1"x1"x.25") with the same result.

It happens with lots of individual items as well as large qtys of a small number of items.

What can be done to optimize the shipping process? And our product is really light, so removing dimensional shipping rates is not an option for us.

Any ideas?

[kobra]

Are there any debug errors in your cache???

Might clear them and try a test again as then any should be related to your time out issue

[JacobBushnell]

asudol, did you ever figure what was causing this? I am having the exact same problem with my UPS shipping estimator using CEON advanced Shipper module.

I'ts blazing fast with orders under 300 lbs. after that it gets really slow. When I have an order over 1,000 lbs it take upwards of 60 seconds to come back!

I have checked the log file and there are no errors...

Jacob