Yeah but the Haswell release has been delayed with the current projection being for June. Won't the push back the IB Xeons? If so, we're looking at a late july or even august release for them. How long can Apple wait for these, especially given that Intel's projections keep slipping?
They have a few different plants to build the chips. Haswell for laptops and desktops is high volume so they need yields to be high to meet 50+ million units in a single quarter. Intel shipped 181 million processors last year (Apple apparently nearly matched them with 176 million). Workstations and servers are only 12 million units a year across all vendors so per quarter, they only need at most 3 million processors and it's on a well established Ivy Bridge fab.
There's a report suggesting the delay was nothing to do with production issues:
"The actual reasons for the delay are unclear, but sources with knowledge of the talks between Intel and its partners among computer makers indicate that the latter had asked the former to postpone the roll-out of Haswell by several weeks to let them sell current-generation Core i 3000 “Ivy Bridge” chips.
Another reason why Intel might be interested in the delay of formal launch of Haswell is that Computex Taipei 2013 trade-show takes place in early June and at that exhibition numerous designs with new chips will be shown to the public.
Intel did not comment on the news-story."
Haswell is already in production:
and someone supposedly got hold of an engineering sample, which came out slower than Ivy Bridge:
which led Francois Piednoel (Principal Engineer / Performance Architect at Intel) to tweet:
"#intel #haswell is very healthy in our labs, we don't see any case where it is slower than IvyB. .ru numbers are funky!"
Ivy bridge E samples seem to be in the open too:
It's all a lie, they're holding them back. #artificialsupplyconstraint
Apple would get dragged over the coals for that but sadly Intel has no competition any more so they get away with it. Given that both are in production, I don't see why they couldn't have both in June.