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You are here: MacNN Forums > Hardware - Troubleshooting and Discussion > Mac Desktops > What do you expect from upcoming update of the iMac

What do you expect from upcoming update of the iMac (Page 2)
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Veltliner  (op)
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Jul 28, 2010, 12:52 PM
 
How great are the improvements in graphics and processors?

Is there any improvement in the memory architecture?
     
kylef
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Jul 28, 2010, 03:23 PM
 
I've been out of touch with tech for a quite a while now, but if memory serves:

Core 2 and Core 4 (45nm) vs Core i3, Core i5 and Core i7 (32nm)
1066MHz DDR3 vs 1333MHz DDR3

As for graphics, it was my understanding that the ATI Radeon 4670 was about 4x better than the 9400M. The new iMacs have the ATI Radeon 5670 but, more importantly, have substantial memory improvements (from shared or 256MB to a dedicated 512MB). That'll really help at 1080p or 2560x1440.
     
Veltliner  (op)
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Jul 29, 2010, 01:14 AM
 
Originally Posted by kylef View Post
I've been out of touch with tech for a quite a while now, but if memory serves:

Core 2 and Core 4 (45nm) vs Core i3, Core i5 and Core i7 (32nm)
1066MHz DDR3 vs 1333MHz DDR3

As for graphics, it was my understanding that the ATI Radeon 4670 was about 4x better than the 9400M. The new iMacs have the ATI Radeon 5670 but, more importantly, have substantial memory improvements (from shared or 256MB to a dedicated 512MB). That'll really help at 1080p or 2560x1440.
i5 and i7 we had before.

Is it the same processor, or did they go from 45nm to 32nm?
     
kylef
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Jul 29, 2010, 06:54 AM
 
I'm pretty sure that the architecture remained unchanged then, as far as I know the Core iX processors were all 32nm from the get-go. I could be wrong though.
     
Veltliner  (op)
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Jul 31, 2010, 11:15 PM
 
Anyway, with glossy monitors only the iMac is out of the question.
     
P
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Aug 1, 2010, 01:16 PM
 
Originally Posted by Veltliner View Post
How great are the improvements in graphics and processors?
I'm glad you asked...

The bottom model: Moves from Core 2 to Core i3 with the same clockspeed and moves up to a Radeon 4670 for the graphics (was GF 9400). The CPU change basically comes down to the addition of Hyperthreading, which can add about 20% on a reaosnably threaded workload. The GPU change is of course significant - this is a more capable, well rounded model than its predecessor.

The middle two models move to a 3.2 GHz Core i3 and a Radeon 5670. The CPU is easy: Hyperthreading, plus a small boost in the higher clockspeed - but we don't really know which GPU that is. Apple uses Mobility Radeons, and there just isn't a Radeon 5670 Mobility available from ATi. Until someone runs a GPU-Z on it, we'll have to guess, and my guess is that they're doing what they used to do with nVidia and use a Mobility chip but describe it as the closest desktop equivalent. In that case, they're probably using a Mobility Radeon 5730. Assuming I'm right, this means 80 more shader processors - a 25% increase from the 4670 in the last model. Along with twice the video memory it's a boost, but nothing earth-shattering.

The BTO options are to a faster version of the same CPU. Don't be fooled by the "Core i5" moniker - it's no quad, it's just a higher clockspeed and a mostly pointless Turbo Boost feature (Turbo Boost for quads means that the CPU overclocks when it has less than 4 threads to handle - a quite common occurance, and the boost when dropping to two cores or less is significant. Turbo for duals only kicks in when there's a single thread active. That is rare, and the boost is smaller anyway)

The top model has only had minor changes. Apple has moved up one clockspeed bin on each model, to a Core i5-760 and Core i7-870, but they haven't changed otherwise. The GPU is the biggest difference here. A newer CPU, with more memory and GDDR5? Awesome! Unfortunately no. It's a Mobility 5850 or some variation of it, and that drops back down to a 128bit memory bus. That means that the update over the last model is tiny if it even exists. We'll have to see the clockspeeds to know, but basically it's the same GPU as last time but with twice the video RAM and some new shader instructions that the Mac drivers don't make use of anyway.

Originally Posted by Veltliner View Post
Is there any improvement in the memory architecture?
No.

Or, well... not really. The top model is exactly the same as last time. The low-end models look very different at first, with the memory controller in the CPU package, but it's still not on the same die, so the memory latency hasn't improved. It's even gone slightly worse, due to the changed cache set up. That cache set up will be a net boost, however - the small dedicated L2 caches are way faster than the big old unified cache - but it's nothing like the change Nehalem brought. That will come with Sandy Bridge, but the upside is that it's only a few months away now.
The new Mac Pro has up to 30 MB of cache inside the processor itself. That's more than the HD in my first Mac. Somehow I'm still running out of space.
     
P
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Aug 1, 2010, 01:20 PM
 
Originally Posted by kylef View Post
I'm pretty sure that the architecture remained unchanged then, as far as I know the Core iX processors were all 32nm from the get-go. I could be wrong though.
Nope. Bloomfield (Core i7-900 series, Xeon 3500 series), Lynnfield (Core i7-800 series, Core i5-700 series, Xeon 3400 series), Clarksfield (mobile quads) and Gainestown (Xeon 5500 series) all launched at 45nm. Bloomfield and Gainestown got a partial successor in the six-core Gulftown at 32nm, but generally were not shrunk. Arrandale and Clarkdale (all the dual core i7/i5/i3, desktop and mobile) launched at 32nm.
The new Mac Pro has up to 30 MB of cache inside the processor itself. That's more than the HD in my first Mac. Somehow I'm still running out of space.
     
kylef
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Aug 3, 2010, 08:36 PM
 
Originally Posted by P View Post
Nope. Bloomfield (Core i7-900 series, Xeon 3500 series), Lynnfield (Core i7-800 series, Core i5-700 series, Xeon 3400 series), Clarksfield (mobile quads) and Gainestown (Xeon 5500 series) all launched at 45nm. Bloomfield and Gainestown got a partial successor in the six-core Gulftown at 32nm, but generally were not shrunk. Arrandale and Clarkdale (all the dual core i7/i5/i3, desktop and mobile) launched at 32nm.
I'm more out of touch than I thought
     
Veltliner  (op)
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Aug 3, 2010, 11:37 PM
 
Originally Posted by kylef View Post
I'm more out of touch than I thought
It's hard to touch 32nm. 45 may be a bit more easy, but still not child's play!
     
P
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Aug 4, 2010, 07:24 AM
 
Originally Posted by kylef View Post
I'm more out of touch than I thought
Don't feel bad, it's more complicated than usual this time. For some reason Intel managed to get their 32nm process up and running before schedule, when everyone else was late (AMD CPUs are still at 45nm, GPUs are still at 40nm), which meant that the Nehalem and Westmere generations ran into each other. There weren't any straight threadshrinks of anything Nehalem, so about half of everything launched at 45nm and the rest at 32nm.
The new Mac Pro has up to 30 MB of cache inside the processor itself. That's more than the HD in my first Mac. Somehow I'm still running out of space.
     
 
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