I wonder if the new iMac will put pressure on Apple for a more reasonably priced Mac Pro, come Sandy Bridge server time.
No, it won't. There is general pressure from the overall PC market for a cheaper mini-tower box. However, that isn't new; that pressure has already been present.
More than a few of those potentially "former" MacPro buys were not really MacPro buyers. They would have been more satisfied spending iMac kind of money ( $1,500-1999) but got pressed into buying a MacPro. There is
no need for MacPro to try to chase after those folks buy lowering the price. Some of those folks were bolting into Windows mini-towers right now. The new iMacs will probably capture more of those folks that were not going to buy Macs. That was the bigger hole to plug.
What Apple needs to do is make sure the Mac Pro has more value features than the iMac for those who have the budget to spend $2,500+ on a box. It still can rest in I/O , just not to low end (common 2010 speeds) disk expansion.
1. PCI-e v3.0 on the MacPro. That would put some distance between TB equipped Macs and the MacPro (whether it gets TB or not). TB is stuck on PCI-e v2.0.
A diagram in at least one article suggests that these new server class Xeons will get PCI-e v3.0 In the "Romley Platform" diagram here :
http://www.cpu-world.com/news_2011/2011050402_Intel_Xeon_E5-1600_and_E5-2600_processor_details.html there is a indication of "up to 40 PCI-e Gen 3.0 lanes"). That is indicate that really the X58 effectively got absorbed by the Xeon package, not pushed into a another "Southbridge"-like chipset (e.g., X79 rumors ).
http://en.wikipedia.org/wiki/File:X58_Block_Diagram.png
The primary duty of the X58 was to provide PCI-e lanes and to provide DMI conduit to "Southbridge"-like support chip. The new diagram suggest that E5s do that all by themselves ( yet another piece of functionality can squeeze in when don't have to implement a "fast" GPU. )
2. Better Video cards with less drama. The iMac tops out at 2MB of VRAM. People with apps that push lots of data to the VRAM will still get more value out of a MacPro. It would also help if there were a wider variety of cards that worked with MacPro. ( Note: PCI-e 3.0 can possible help here also with either a GPU + TB combo card option or just GPU card with just that more bandwidth. ).
Also can get RAID and Network cards with higher bandwidth.
3. Soak up part of the XServe market: rackable case , lights-out management, etc.
Get more value out of more than 4 cores: more parallelized software (FinalCut X ) and OS support, etc.
More diverse I/O without additional external dongles ( e.g., USB 3.0 )
The Mac Pro can be priced higher if it offers more value. Most people will pay more to get more value. The problem of the overall PC market prices going down is present for the whole Mac line up. Cheaper MacPros won't come until cheaper iMacs do which in turn are held up by cheaper Mac Minis ( and iPads ).
What Apple could do to incrementally help would be to start the Mac Pros off in the $2,100-2,200 range. Since the iMacs standard configs stop at $1,999, MacPros can climb down a small amount without breaking their "no price overlap" law. Right now they provide the 27" i7 option a bigger window.
(For those here who are not into graphics, video pretty much requires TWO fast ports: one for imputing video, and second for looping it onto an external hard drive. One of the two ports is usually much faster than FW800, for use with a RAID drive).
You don't need two. What you need is enough bandwidth. For HD workflows one TB controller will work. And it isn't two ports. Two FW ports that operate off the same controller have the same bandwidth as just one port. For example, the new 21" and 27" iMacs have exactly the same TB bandwidth. There is more connection convenience with the two port 27" set-up but not more bandwidth.
In practice with older MacPros you needed an additional FW/eSATA/etc. in a PCI-e slot to get the incremental step in bandwidth. However, that confusing the implementation (card/port) for the root cause problem (bandwidth).
At least the current iMac is more than enough for incredibly easy to run and somewhat underpriced broadcast standard NLE, Final Cut Pro 7
Depends. If there is centralized storage it still may be easier to use a MacPro than an iMac. For example tapping into legacy XSan or a 10Gb Ethernet set up. Likewise FCP 7 is core choked. The iMacs max out at 4 so not an issue now. In the next generation it will be a larger differentiator.
Sure some users will peel off into iMacs. But it is bigger issue to better compete head-to-head with the other $3,000+ workstations and their workloads.