> What kind of Megaherts do you get out of there chips

The fastest ARM core to date is the Cortex-A9, which is specified at up to 2.0 GHz:

http://en.wikipedia.org/wiki/ARM_Cortex-A9_MPCore
http://www.arm.com/products/processors/cortex-a/cortex-a9.php

Actual chips however based on that core currently reach only up to about 1.5 GHz. There's a Chinese company that claims it can deliver 2.0 GHz right now but I don't know if that claim is really true:

https://morph.zone/modules/newbb_plus/viewtopic.php?forum=3&topic_id=7183&start=310

> are they dual core

Chips based on Cortex-A9 can have up to 4 cores. Current chips in volume production have only up to 2 cores but there're some announced or maybe even sampling with 4 cores.

> how fast are they

As always, that depends on how you measure and quantify it. In terms of Dhrystone benchmark the Cortex-A9 delivers 2.5 DMIPS per MHz.

> can you get ARM cpus without graphics built in or are we
> all gunna use same one?

There're chips based on Cortex-A9 without on-chip 3D GPU but with on-chip PCIe controller, for instance:

http://www.st.com/internet/mcu/product/250658.jsp
http://www.xilinx.com/products/silicon-devices/epp/zynq-7000/

Furthermore, there're some with on-chip 3D GPU *and* on-chip PCIe controller:

http://www.st.com/internet/mcu/product/251211.jsp
http://www.samsung.com/global/business/semiconductor/productInfo.do?fmly_id=844&partnum=Exynos%204210 (see block diagram)
http://www.google.com/search?q=site:developer.nvidia.com/tegra/+pcie (nVidia doesn't seem to promote its PCIe capability much)

> most of the other g5's are 64 bit.

*All* G5 aka PPC970 chips are 64-bit. What do you mean by "other"?

> Maybe it would be a good idea to switch to ARM as it is
> alot cheaper?

Old G5 Macs are still faster than the fastest ARM machine and become cheaper by the minute ;-)

> give me your feedback

You're welcome.