In this post, we discuss the hardware recommendations for Forefront TMG, based on the number of users and deployment scenario. Enabling different features on Forefront TMG carries different costs. When considering the hardware required for your deployment, take into account the projected growth of your organization and the Internet’s increasing bandwidth demands. The recommendations that follow are based on an allocation of 100 kilobits per second (Kbps) per user during peak time.

In this post:

· Design server hardware generously

· CPU considerations

· Storage considerations

· Network adapter considerations

· Redundancy recommendations

· Typical configurations

Design server hardware generously

Design your server hardware according to current and future requirements to prepare for future growth. You might want to consider additional processors, additional memory, and a reliable storage subsystem that has a capacity of at least two or three times your estimated requirements. Note that hardware technology evolves at a rapid pace. Within a relatively short period of time, upgrade options might not be available for your server platform, which can pose a serious problem if future demands require you to increase system performance; for example, in the event that you need additional processors.

--> The rest is on the blog :

http://blogs.technet.com/isablog/archive/2010/01/12/hardware-recommendations-for-forefront-tmg-2010.aspx