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MisterAndrew

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There are four GeekBench 4 benchmark scores for the iMac Pro in 2 variants.

The first one with benchmark scores from August 22, is a Pro Vega 56 variant with 8GB of memory. Here are the details:
-CPU: Single unknown Intel 8 core, Family 6 Model 85 Stepping 2 with 2.40 GHz base frequency and 11MB of L3 cache
-RAM: 128GB 2666 MHz DDR4
-BIOS: AAPJ1371.88Z.E087.B00.1708170938
-macOS version: 10.13.1 (Build 17B2024)

The second one with benchmark scores from September 29, is a Pro Vega 64 variant with 16GB of memory. Here are the details:
-Single Intel Xeon W-2150B 10 core, Family 6 Model 85 Stepping 4, with 3.00 GHz base frequency and 13.8 MB of L3 cache.
RAM: 64GB 2666 MHz DDR4
BIOS: AAPJ1371.88Z.E064.B20.1709261741
macOS version: 10.13.2 (Build 17C32)

Both have model identifier AAPJ1371,1 and logic board Mac-7BA5B2D9E42DDD94.

The OpenCL score for the Pro Vega 56 model is on par with the RX Vega 56 installed in my Mac Pro 5,1. The 2 scores are 149624 and 150639. Mine scored 152085. According to the specs, the Pro Vega 56 in the iMac Pro is underclocked at 1.25GHz compared to the RX Vega 56 which is clocked at 1.59GHz. The iMac Pro's Pro Vega 64 is clocked at 1.35GHz.

Screenshots of the 2 different variants, plus my cMP for comparison.

Geekbench 4 Vega 56.jpeg Geekbench 4 Vega 64.jpeg Geekbench 4 OpenCL full.jpeg
 
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EugW

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Assuming it’s legit... I can’t find any specs for the W-2150B. The closest I can find is W-2155 which is 3.3 GHz.

Could W-2150B at 3 GHz be a lower power SKU?

As suspected, it has no integrated GPU. I wonder how they will handle HEVC decode and encode. Software based only? With 8+ cores the W series could do it in software but that could turn the fan up to 11, esp. given its 140W TDP. Or would they write drivers that leverage GPU-based hardware HEVC support only on Vega, and not bring it to the consumer AMD GPU models in iMacs and MacBook Pros?

Interestingly, the W-21xx series are Skylake based. The Skylake iMacs, MBPs, and MBs do only 8-bit hardware HEVC decode so this would deviate from that. The CPU has no hardware decode at all, but the GPU could do full 10-bit if Apple were to implement that.
 

joema2

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....As suspected, it has no integrated GPU. I wonder how they will handle HEVC decode and encode. Software based only? With 8+ cores the W series could do it in software but that could turn the fan up to 11...

Yes, this is the million-dollar question. The only CPU > 4 cores with Quick Sync is Intel's 6-core i7-8700K, which is announced but not yet shipping: https://ark.intel.com/products/126684/Intel-Core-i7-8700K-Processor-12M-Cache-up-to-4_70-GHz

The benefit of Quick Sync is it's built into the CPU, companies already have software written for that, performance is 4x or 5x better than software methods (for H264 -- maybe much greater for H265), and if used properly the video quality is excellent. The downside is except for the i7-8700K, Quick Sync is unavailable on any CPU > 4 cores -- including all 6-core and above Xeons. Both iMac Pro and the upcoming modular Mac Pro will use Xeon.

Apple's only solution may be to break down and write software for AMD's proprietary Unified Video Decoder (UVD) and Video Coding Engine (VCE), which is on AMD GPUs: https://en.wikipedia.org/wiki/Unified_Video_Decoder

If they don't do this the iMac Pro and even the next Mac Pro will be very slow handling 4k H264 and H265/HEVC. That was less an issue in the past when things were more 1080p-based and HEVC streaming content was a future dream.

Unfortunately (unlike Quick Sync) even the latest Vega version of AMD's UVD and VCE don't handle Google's VP9 and I assume the successor AV1 codecs. Youtube is transitioning to that, although there will be fall-back codecs for clients that cannot support those.
 
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EugW

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Yes, this is the million-dollar question. The only CPU > 4 cores with Quick Sync is Intel's 6-core i7-8700K, which is announced but not yet shipping: https://ark.intel.com/products/126684/Intel-Core-i7-8700K-Processor-12M-Cache-up-to-4_70-GHz
All the mainstream desktop 6-core models support Quick Sync. These are the ones that will show up in the new iMac, and include i5 chips like the 8600K and 8400, etc.

If I could have waited I would have gotten a 6-core i5 in 2018, but I couldn’t wait unfortunately.

My favourite chip on paper is the hexacore i7-8700 non-K but I suspect that won’t be in a 27” iMac, just the 21.5” or equivalent.

But no, they won’t be in the iMac Pro.
 

joema2

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All the mainstream desktop 6-core models support Quick Sync. These are the ones that will show up in the new iMac, and include i5 chips like the 8600K and 8400, etc.

If I could have waited I would have gotten a 6-core i5 in 2018, but I couldn’t wait unfortunately...

Thanks for that correction. It's not just the Coffee Lake 6-core i7-8700K but the 6-core i5-8600K and the 6-core i5-8400 that will also have Quick Sync -- when they are finally released in the near future.

Coffee Lake i5-8600K https://ark.intel.com/products/126685/Intel-Core-i5-8600K-Processor-9M-Cache-up-to-4_30-GHz
Coffee Lake i5-8400: https://ark.intel.com/products/126687/Intel-Core-i5-8400-Processor-9M-Cache-up-to-4_00-GHz

This is the first time ever that Quick Sync has been available on a > 4 core CPU. Unfortunately it does not (thus far) include future Xeon CPUs and no Intel roadmap, rumor or guidance addresses this issue. The current Xeon-W CPUs rumored for the iMac Pro do not have Quick Sync: https://www.macrumors.com/2017/08/29/intel-debuts-new-xeon-w-chips/

This will increasingly be a major issue in the future, especially as 4k H264 and HEVC becomes more common. Really high end productions such as a $100 million Hollywood movie are not impacted -- they use ProRes, DNxHD or RAW acquisition. Likewise smaller scripted productions with lower shooting ratios are not impacted -- they also can acquire in those lower-compression codecs.

Smaller Youtube vloggers shooting H264 or HEVC will probably be using MacBook Pros and iMacs which have Quick Sync. The ones impacted will be all those in the middle, e.g, medium-to-large-scale documentary productions with high shooting ratios who cannot reasonably use ProRes or DNxHD acquisition, and would normally consider an iMac Pro or upcoming modular Mac Pro.

That's the production side. On the consumption side, as streaming video increasingly moves to HEVC and AV1, I suppose Mac users can continue using regular iMacs and MacBook Pros for that. New Smart TVs and new mobile devices will have HEVC hardware decoding built in. But lots of people consume streaming video on their laptop or desktop. Unless something changes they might have trouble using their new iMac Pro for this.
 
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EugW

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Thanks for that correction. It's not just the Coffee Lake 6-core i7-8700K but the 6-core i5-8600K and the 6-core i5-8400 that will also have Quick Sync -- when they are finally released in the near future.

Coffee Lake i5-8600K https://ark.intel.com/products/126685/Intel-Core-i5-8600K-Processor-9M-Cache-up-to-4_30-GHz
Coffee Lake i5-8400: https://ark.intel.com/products/126687/Intel-Core-i5-8400-Processor-9M-Cache-up-to-4_00-GHz

This is the first time ever that Quick Sync has been available on a > 4 core CPU.
There's also the i7-8700 as mentioned, but besides those I mentioned, I suspect a bunch more 6-core mainstream chips suitable for the iMac will be announced tomorrow. The Coffee Lake official launch isn't until Oct. 5.

Here is a review of the 8700K:

http://lab501.ro/procesoare-chipset...5-8600k-coffee-lake-aorus-z370-ultra-gaming/8

Since you're most interested in video encoding, here is the Handbrake result for the 8600K and 8700K:

Handbrake-1.jpg


Interestingly, the 8700K is only 6% faster than the 7700K in their Handbrake test.

However, for stuff like 3D Studio MAX and Cinebench, it's hugely faster.

3dsmax.jpg


Ray1-1.jpg


You'll also note that the 8600K is also faster than the 7700K in these tests.

Officially, there is currently no 8500 6-core, but I suspect it will be announced tomorrow. An 8500 6-core or an 8600 non-K 6-core is what I would likely buy (assuming they get announced), if I were to buy an iMac in 2018.

Unfortunately for me, it came down to me either getting a big tax break buying in 2017, or else getting a small tax break in 2018. The other issues are I wanted Quick Sync for 8-bit 4K HEVC coming out of my iPhone, and the HD in my 2010 iMac was killing me (and I didn't feel like spending $$$ to put a big SSD in my 2010 iMac).
 
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Jack Burton

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If these numbers are legit, the 8700k looks fantastic. Single thread is king and the cinebench score is impressive for 6 cores vs Ryzen's 8.
 

EugW

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If these numbers are legit, the 8700k looks fantastic. Single thread is king and the cinebench score is impressive for 6 cores vs Ryzen's 8.
If the heat characteristics are similar to the 7700K, and the new 8th gen Intel iMac's cooling design is similar to current models, I personally would stay away from the 8700K, due to fan noise concerns.

But that's just me. I'm one of the guys who bought a 7700K and then returned it for a 7600 non-K to get a quieter machine. Your needs and preferences will differ from mine.
 

Jack Burton

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If the heat characteristics are similar to the 7700K, and the new 8th gen Intel iMac's cooling design is similar to current models, I personally would stay away from the 8700K, due to fan noise concerns.

But that's just me. I'm one of the guys who bought a 7700K and then returned it for a 7600 non-K to get a quieter machine. Your needs and preferences will differ from mine.

We got a 7700k 27 inch in my office, Finally got a refurb and threw in some 3rd party ram. Lovely machine - wicked fast, but when I ran cinebench on it multiple times, it was noticeably louder than my 2011. My office is extremely loud, so I probably won't notice unless I'm working late and everyone else is gone. Anyone else that taxes the system and works in a quiet environment will notice.

My coworker who works across from me and faces the back of my iMac will probably notice when she isn't using her noise canceling headphones.

I'd love the 8700k in an iMac enclosure. But I fear giving it the cooling it needs means using the cooling solution of the iMac Pro and losing ram upgradeability (basically the cost may just become more ridiculous)

EDIT: ars technica reviewed the 8700k. Heat's an issue. I got my hopes up, and I was considering this processor in a pc or an iMac. But it sounds like heat's an issue at stock speeds!

At stock speeds on auto settings, the 8700K reaches a toasty 90°C under full load when paired with a substantial 280mm liquid cooler (in this case a CoolerMaster MasterLiquid Pro). I had paired the 8700K with a 240mm liquid cooler, but that wasn't enough to keep the temperatures down.

SNIP

Good air coolers like the Noctua NH-D14 and 280mm liquid coolers are recommended, with overclocking requiring further cooling still. That it's possible to reach 5.0GHz across six cores is impressive-but it's clear that with a better method of transferring heat away from the die, Coffee Lake could be pushed further.
 
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MisterAndrew

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Assuming it’s legit... I can’t find any specs for the W-2150B. The closest I can find is W-2155 which is 3.3 GHz.

Could W-2150B at 3 GHz be a lower power SKU?

As suspected, it has no integrated GPU. I wonder how they will handle HEVC decode and encode. Software based only? With 8+ cores the W series could do it in software but that could turn the fan up to 11, esp. given its 140W TDP. Or would they write drivers that leverage GPU-based hardware HEVC support only on Vega, and not bring it to the consumer AMD GPU models in iMacs and MacBook Pros?

Interestingly, the W-21xx series are Skylake based. The Skylake iMacs, MBPs, and MBs do only 8-bit hardware HEVC decode so this would deviate from that. The CPU has no hardware decode at all, but the GPU could do full 10-bit if Apple were to implement that.

It’s typical for Intel to make processors for OEMs that they don’t publicly release specs for.
 

joema2

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It’s typical for Intel to make processors for OEMs that they don’t publicly release specs for.

So far Intel's custom CPU mods for large OEMs have been architecturally minor -- an additional or modified instruction here or there, a slightly tweaked turbo boost algorithm. etc. To my knowledge Intel has never made a major architectural change for an OEM, such as adding the on-chip GPU required for Quick Sync to a high-core-count Xeon. That would effectively be a new design which would require all the cost, validation and testing of a new design, yet be possibly only sold by one OEM.

The CPU design cost would possibly be about $80 million, and testing and integration to would be more. Then whenever they start a fabrication run they are only making the chips for one customer -- having paid that huge price the OEM doesn't want to Intel giving that edge away to their competitors. The OEM paid for the job so they get to dictate the terms. Thus Intel (and the large OEM paying for the custom design) cannot amortize the cost over many millions of chips, yet that's the basis for the semiconductor industry financial system. This makes the per-chip cost very high and even a stock Xeon is already expensive. Since Apple only uses those in a small % of their computers, the cost recovery would seem difficult.

It would seem a lot cheaper for Apple's programmers to write to AMD's UVD/VCE video transcoding hardware that's already present on their GPUs. They'd have to maintain this in parallel with Quick Sync but they could keep control over that as a competitive advantage on their Xeon-based systems.
 
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MisterAndrew

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So far Intel's custom CPU mods for large OEMs have been architecturally minor -- an additional or modified instruction here or there, a slightly tweaked turbo boost algorithm. etc. To my knowledge Intel has never made a major architectural change for an OEM, such as adding the on-chip GPU required for Quick Sync to a high-core-count Xeon. That would effectively be a new design which would require all the cost, validation and testing of a new design, yet be possibly only sold by one OEM.

The CPU design cost would possibly be about $80 million, and testing and integration to would be more. Then whenever they start a fabrication run they are only making the chips for one customer -- having paid that huge price the OEM doesn't want to Intel giving that edge away to their competitors. The OEM paid for the job so they get to dictate the terms. Thus Intel (and the large OEM paying for the custom design) cannot amortize the cost over many millions of chips, yet that's the basis for the semiconductor industry financial system. This makes the per-chip cost very high and even a stock Xeon is already expensive. Since Apple only uses those in a small % of their computers, the cost recovery would seem difficult.

It would seem a lot cheaper for Apple's programmers to write to AMD's UVD/VCE video transcoding hardware that's already present on their GPUs. They'd have to maintain this in parallel with Quick Sync but they could keep control over that as a competitive advantage on their Xeon-based systems.

I agree. I didn’t make any claims about video transcoding.
 

joema2

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Yes, and you'll be able to cook your eggs on it in the morning. ;)

From the current specs the TDP is 95 watts, only 4 watts over the 91 watts of the i7-7700K or i7-6700K.

By contrast the Xeon-W CPUs to be used in the upcoming iMac Pro have a TDP of 120 watts.
 

Glideslope

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From the current specs the TDP is 95 watts, only 4 watts over the 91 watts of the i7-7700K or i7-6700K.

By contrast the Xeon-W CPUs to be used in the upcoming iMac Pro have a TDP of 120 watts.

Let's not forget the Vega Graphics in that enclosure either. The iMac Pro will make a nice office warmer on cold days. ;)
 

joema2

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Where did you find the TDP spec for the W-2150B?

It is possibly 140 watts, not 120. The parts likely to be used in the iMac Pro are the 8-core W-2145, the 10-core W-2155 and the 18-core W-2195. Of course there could be slight variants of these but the fabrication physics, voltage and clock rate determine the TDP, and it is very difficult to change that much.

http://appleinsider.com/articles/17...ocessors-likely-to-be-used-in-apples-imac-pro

https://www.anandtech.com/show/11775/intel-launches-xeon-w-cpus-for-workstations
 

MisterAndrew

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It is possibly 140 watts, not 120. The parts likely to be used in the iMac Pro are the 8-core W-2145, the 10-core W-2155 and the 18-core W-2195. Of course there could be slight variants of these but the fabrication physics, voltage and clock rate determine the TDP, and it is very difficult to change that much.

http://appleinsider.com/articles/17...ocessors-likely-to-be-used-in-apples-imac-pro

https://www.anandtech.com/show/11775/intel-launches-xeon-w-cpus-for-workstations

That’s speculation. What we have evidence for is that the 10 core model is called W-2150B. It appears to be a lower clocked version of the W-2155. Also based on the evidence we have, the 8 core model is a lower clocked version of the W-2145, and we don’t know the name of it yet.
 

joema2

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That’s speculation. What we have evidence for is that the 10 core model is called W-2150B. It appears to be a lower clocked version of the W-2155. Also based on the evidence we have, the 8 core model is a lower clocked version of the W-2145, and we don’t know the name of it yet.

Of course it's speculation. The name of this site is Mac Rumors. Apple states on their web site the iMac Pro will be Xeon based and up to 4.5 Ghz turbo boost -- the exact turbo boost numbers of the 8 and 10-core Xeon-W parts.

It's possible they could slightly lower the base clock and maybe still retain the promised turbo boost number, which would reduce power consumption a bit. We don't really know -- that's speculation.
 
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MisterAndrew

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I noticed the CPU benchmarks for the iMac Pro on Geekbench 4 as well. The single-core performance of the Xeon W-2150B trails behind the Core i7-7700K in the standard iMac with a score of 5345 vs. 5680, but excels in multi-core performance with a score of 35917 vs. 19335, which is to be expected with 10 cores. That also puts it well ahead of the 12 core Xeon E5-2697 in the 2013 Mac Pro which has the highest multi-core score of any current Mac at 25446. The scores for the iMac Pro 8 core model are not as impressive with 3826 for single-core and 23676 for multi-core.

iMac Pro 10 Core: https://browser.geekbench.com/v4/cpu/4449687

iMac Pro 8 Core: https://browser.geekbench.com/v4/cpu/3775178

Update: We have a name for the 8 core CPU. It's a Xeon W-2140B. (Listed in this benchmark result: https://browser.geekbench.com/v4/compute/1217237)
[doublepost=1507944563][/doublepost]According to this article, the B variant Xeon processors may have integrated graphics.

https://pikeralpha.wordpress.com/20...apples-new-imac-pro-with-special-xeon-w-skus/
 
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Redneck1089

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I noticed the CPU benchmarks for the iMac Pro on Geekbench 4 as well. The single-core performance of the Xeon W-2150B trails behind the Core i7-7700K in the standard iMac with a score of 5345 vs. 5680, but excels in multi-core performance with a score of 35917 vs. 19335, which is to be expected with 10 cores. That also puts it well ahead of the 12 core Xeon E5-2697 in the 2013 Mac Pro which has the highest multi-core score of any current Mac at 25446. The scores for the iMac Pro 8 core model are not as impressive with 3826 for single-core and 23676 for multi-core.

iMac Pro 10 Core: https://browser.geekbench.com/v4/cpu/4449687

iMac Pro 8 Core: https://browser.geekbench.com/v4/cpu/3775178

Update: We have a name for the 8 core CPU. It's a Xeon W-2140B. (Listed in this benchmark result: https://browser.geekbench.com/v4/compute/1217237)
[doublepost=1507944563][/doublepost]According to this article, the B variant Xeon processors may have integrated graphics.

https://pikeralpha.wordpress.com/20...apples-new-imac-pro-with-special-xeon-w-skus/


Wow, I’m really surprised by the low single-core score of the 8-core.
 

iPadified

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I do not understand these benchmarks at all. The 10-core ST performance is 5345 but clocked lower than the 8-core chip. I was expecting almost 7700K performance for up to ”4.5 GHz” as state in Apple home page. That the 10-core runs at 4.5 GHz but not the 8-core seem very strange. A jump from 23676 to 35917 MT for 2 additional cores does not make any sense either.
 

Trebuin

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I do not understand these benchmarks at all. The 10-core ST performance is 5345 but clocked lower than the 8-core chip. I was expecting almost 7700K performance for up to ”4.5 GHz” as state in Apple home page. That the 10-core runs at 4.5 GHz but not the 8-core seem very strange. A jump from 23676 to 35917 MT for 2 additional cores does not make any sense either.

You caught the fact that at least one of the two computers is not a real Mac. Unless Apple has chosen to severely cripple the 8 core & sell us a cheap chip to make extra money, the lower core should always run faster. When you use the same chip generation with the same restrictions, the higher number of cores increase the heat, but handles multi-core more efficiently. Because of this, they solve the issue by dropping the clock. This is not the first time a fake benchmark has shown up (not the OP's fault).

The base frequencies will likely be 3.7 & 3.3 for the 8 & 10 core respectively. Don't quote me on this, but the chips with these speeds are the most likely candidates that have been quoted. Most of the other ones don't support ECC memory or meet the power requirements the iMac would likely support.

Excellent job for pointing this out.
[doublepost=1508035188][/doublepost]There's been some talk about HEVC above, I have encoded HEVC using intel's quick sync, but it's nowhere near as nice as a software encode. This surprised me.
 
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