It's based off Facebooks API, which is on Facebooks server as well as it's communicating with Facebook. So it's purely based off how well their servers are performing for the time being. You will have a performance hit by using it; there's no getting around that. As for worse performance in IE is because it's a horrible browser. There's really no way to fix it. You can speed up the process by having a faster host, but that'll only help so much.