suPHP vs. FastCGI


New Member
Hey all,

My existing KnownHost VPS plan has 3GB of memory and 8 cores.

I'm moving dozens of average traffic sites over from shared hosting to this new VPS and, on my shared hosting platform, the sites were using FastCGI. My KnownHost VPS is currently configured as suPHP, but support has informed me that they can re-compile FastCGI if I specifically request it.

Everything I've read suggests that suPHP uses less memory and more CPU, and FastCGI uses more memory and less CPU. My question is, with 3GB of memory on this plan is switching from suPHP to FastCGI worth it? With 3GB would I have enough memory? With 8 cores should I just stick with suPHP?

Appreciate your input, especially if you've tried FastCGI already on your VPS and can provide some feedback based on your results.

Your findings are correct in that the suPHP uses more CPU, while FastCGI uses more memory.

Generally the speed of each will be so close you can't tell a difference. 3GB of RAM could be enough RAM for FastCGI, but it all depends on traffic.

I've heard that FastCGI's performance will actually degrade under load worse than suPHP's, but I can't really attest to this as I personally always use DSO for it's superior performance for my personal sites.
My VPS just had an issue with FastCGI where there was a bug with Cpanel and it's configuration. I recently just switched back to SuPHP and everything is working pretty flawlessly. I'm also utilizing Rackspace Files CDN and I set it up for all of my customers websites, it's a small price to pay but I've seen it decrease the load on the server for my clients.

Jonathon, I've been reading up on these different PHP handler, why do you personally use DSO? Is it better than SuPHP in your humble opinion?
DSO is the fastest handler, as it has the least overhead. It's also the most insecure in a shared hosting environment, and when not properly locked down - so when hosting customers, suPHP or FastCGI is the way to go. When only hosting yourself - DSO is where it's at.
Thanks Jonathan, you are very knowledgeable! I'll keep this in mind if I ever find myself having a dedicated server for one website. For now, I think I'll stick with suPHP as I haven't had anymore problems since making the switch from FastCGI.