The New Dell Precision workstations based on the Intel Xeon E5-2600 series are now available to order in the US and Europe (I haven't checked other locations). It seems reasonable to assume that creating a spec for a Dell Precision T5600 Workstation should give some clues to what Apple might offer in terms of CPUs on BTOs. So here goes: Single CPU: For the high end options the pricing gets interesting. Six Core XEON E5-2667, 2.9GHz, 15M, 7.2 GT/s, Turbo [add $2,081.00] Eight Core XEON E5-2680, 2.7GHz, 20M, 8.0 GT/s, Turbo+ [add $2,196.00] The 8-Core is much better value for money at the top end. Both these chips Max Turbo Frequency is 3.5GHz, so for almost no extra cost you get another 2-Cores giving theoretically 33% extra performance on for applications that can make use of them with no hit on tasks that only run on a single core. Conclusions for Mac Pro There will be no single Quad-Core configurations. Apple will raise the entry price by around 300 to 400 USD. Base configuration will be a single CPU Xeon E5-2620 6-Core 2.0GHz. Apple will offer a BTO options of faster single CPU 6-Core and single CPU 8-Core. Dell's estimated shipping date of 3rd week of July. Maybe Apple can beat them to it!