what is the ideal memory limit for php? I believe mine is 256, 

256 is fine

128MB is our recommended setting. 

128MB is generally the standard recommendation for most PHP applications and is also the default memory limit setting for PHP itself. The only time I've ever needed to raise this above 128MB for IP.Board was because of a third party application.

Generally, don't raise this above the default unless you have a good reason to.

I raised mine to 256M since someone tried posting a topic which was very, very long.

I've found in the past that a higher value of 256MB or 512MB can really help if your using Gallery and need it to upload then resize large original size camera photos, as 128MB used to hang with a white page.

I've found in the past that a higher value of 256MB or 512MB can really help if your using Gallery and need it to upload then resize large original size camera photos, as 128MB used to hang with a white page.

You're really far better off using ImageMagick instead of trying to up the memory limit for GD, GD has an exponential memory requirement after a certain point that becomes impossible to scale with.

GD is fine for simple image processing, but if you need to work with very large images you should really use ImageMagick instead.

Thanks Kirito, I'll give it a try.