How can these CPUs compare to each other regarding the following areas:
Gaming (I know already that these systems are not for serious gamers)
I don't know a lot from the Virtualization World, but the i3-2100 DOESN'T support the following features: (this statement doesn't mean either that the AMD ones support similar features)
- Intel® Trusted Execution Technology (Intel® TXT)
Intel® Trusted Execution Technology for safer computing is a versatile set of hardware extensions to Intel® processors and chipsets that enhance the digital office platform with security capabilities such as measured launch and protected execution. Intel Trusted Execution Technology provides hardware-based mechanisms that help protect against software-based attacks and protects the confidentiality and integrity of data stored or created on the client PC. It does this by enabling an environment where applications can run within their own space, protected from all other software on the system. These capabilities provide the protection mechanisms, rooted in hardware, that are necessary to provide trust in the application's execution environment. In turn, this can help to protect vital data and processes from being compromised by malicious software running on the platform.
Intel® Virtualization Technology (Intel® VT) for Directed I/O (Intel® VT-d)
Intel® Virtualization Technology for Directed I/O (VT-d) extends Intel's Virtualization Technology (VT) roadmap by providing hardware assists for virtualization solution. VT-d continues from the existing support for IA-32 (VT-x) and Itanium® processor (VT-i) virtualization adding new support for I/O-device virtualization. Intel VT-d can help end users improve security and reliability of the systems and also improve performance of I/O devices in virtualized environment. These inherently helps IT managers reduce the overall total cost of ownership by reducing potential down time and increasing productive throughput by better utilization of the data center resources.
To have access to these features in an Intel CPU you need to stick with an i5 or i7 CPU, but only the non-k versions, i.e., i5-24XX, i5-25XX and i7-2600 only.
I will talk about gaming... the apus of AMD can handle a lot more of gaming that any intel cpu without discrete video card... you can play almost any game at low details without much problem... and even some in medium details... something that with intel hd is not possible... also you have the benefit even if you decide to go for a low end discrete... you can crossfire the apu with a 6670(cheap as hell) for example and this will work like a 6790 gpu so at least for game your best choice are the amd apus...
Go with the Intel CPU if you think there's a possibility of gaming in the future. An awesome GTX560Ti is only $250 now.
I recommend the APU only for laptops and for desktops which people absolutely know they won't upgrade.
Forget about attempting to "crossfire" an APU solution. It's likely possible, but Crossfire has micro-stuttering even in the best solutions and horrible stuttering issues in low-end Crossfire solutions.
*You may even discover you wish to add more processing in the future in the form of a graphics card for video conversion. I'm not impressed with anything (mainly software) but the OpenCL (not OpenGL) initiative is pushing things in the right direction.
And, again, it's nice to get five years out of a computer especially if you've left the door open for a graphics upgrade.
**Graphics and Power Supply:
Even if you don't get a nice graphics card right away, I recommend you shop around and get a PSU that can handle about 50Amps on the +12V rail rather than have to buy a new one later.
A 750Watt (total) with 50Amps on the +12V rail should cost roughly $100. Read customer comments, reviews, and look for sales.
If you look at NCIX, you can actually get a quality PSU on sale for $40 (Antec) that may suit your needs. If you don't think you'll get a graphics card for a while this may be the way to go because:
a) you can take the time to shop for a great sale price and review
b) it's always good to have a spare PSU for troubleshooting