over clocking survey

Don't include me in the typically rediculous Bumhard generalisations.

Of course it is possible to do what you want with the chip you want. It may be slow and you may have to add more support hardware to achieve it. You may even find that your at89c51 ends up being the controller of a multi-processor configuration, but it could be done.

Now the question really is whether you are the best candidate for the operation. What do you think?

Don't include me in the typically rediculous Bumhard generalisations.

Of course it is possible to do what you want with the chip you want. It may be slow and you may have to add more support hardware to achieve it. You may even find that your at89c51 ends up being the controller of a multi-processor configuration, but it could be done.

Now the question really is whether you are the best candidate for the operation. What do you think?

I rather suspect that speed will be the least of your problems:

The AT89C51 has only 4K Flash and 128 bytes RAM - you are certainly not going to be able to do all that stuff without external memory expansion!

Possibly not even with the full 64K expansions - so then you'd have to be messing about with banking.
The learning curve for banking is not trivial...

You'd avoid all of that (and save money) with an appropriate processor choice!

Or why not get a Raspberry Pi?
http://www.raspberrypi.org/

The big issue here. Do you want to build one or many devices?

If one - get a development board with ethernet hardware and a prototype area.

If many - get a development board with ethernet hardware and a prototype area. When you are happy: make custom circuit using that CPU.