macduke
macrumors G5
Isn't the main difference for encoding or something? I could possibly test render times for a codec that supports the faster mode vs. one that doesn't and see if there is some kind of advantage.
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2019 iMac i5-9600K/i9-9900K or i5-9600KF/i9-9900KF?
- Thread starter JacobHarvey
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Apparently the KF are K processors with faulty internal graphics and they are still selling them to keep up with demand.
I don’t know if it really matters but when I bought it I was thinking the i9 was a 9900K with internal graphics. Not saying my 580x graphics card will fail but if it ever does it would be nice to use the internal graphics to get by.
My i9 iMac arrives soon.
macduke
macrumors G5
Yeah but Linus Tech Tips was saying they used KF CPUs, which I assume they would have used a utility to test that. And they said that is how Apple is keeping things cooler by not having to run that part of the CPU. So Apple would want to keep each unit similar, and keep each unit cool, and mine runs fairly cool, so they must be disabling the integrated GPU, right? And if they are disabling the integrated GPU, wouldn't the encoding acceleration stuff be disabled? And I think that's the point of this thread. So it could be put to rest once and for all if I could run some sort of test. I'm just not sure what thing I should be testing for people. I think my iPhone records h.265 HEVC 4K and my Sony a7R III records regular h.264 4K but at a little bit higher bitrate.
Enjoy your i9 iMac. My buddy just ordered one yesterday, same specs as me but with the 1TB SSD, and it's not supposed to get here for a couple weeks, which he seems kinda bummed about. I might have him run CPU-Z out of curiosity once I help him get Bootcamped Windows up and running on an external drive which is gonna be a PITA.
I just received my new iMac a little while ago. Looks like it's a 9900K and it does list both Radeon Pro 580X and Intel HD Graphics CFL.
Based on what I've seen from this thread I am 99% sure that Apple is using regular K series processors (it would be pretty crappy for Apple to run another chip lottery so that some get QuickSync and others don't on such a high end and pricey machine). Linus most likely mis-spoke
The i9-9900KF jerwin posted came from a PC which he just posted to show that CPU-Z is indeed capable of differentiating between K series and KF series processors in the "Specification" box of the CPU pane (rather than labelling them all as just 'K' series ones).
Apple seems to just disable the integrated graphics in bootcamp using software (rather than using hardware disabled KF processors) however if you are bothered to run tests in macOS, those would probably help confirm that QuickSync is definitely enabled in mac OS for certain apps (e.g. Compressor). Only bother with this if you are really keen on settling this - I'm pretty sure QuickSync will be working in those apps through a special API Apple uses in macOS.
Another thing that I would be interested in is the motherboard chipset apple used and whether they upgraded the four USB-A ports to 3.1 Gen 2 (10Gbps) speed to save iMac owners having to waste thunderbolt ports on connecting USB SSDs (if you want to get closer to their full potential).
This would probably be a bit time consuming to test properly though, however if you or anyone else has got a moment, a screenshot of the 'mainboard' panel of CPU-Z would help determine if the motherboard at least has the capability for USB 3.1 Gen 2 speeds. Thanks anyway for your bootcamp screenshots so far! I hope to purchase one a bit later in the year
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Bohemien
macrumors regular
I ran Geekbench 4 on my iMac and the device info shows it's a i9-9900K processor. On the GPU benchmark pane, it shows two GPUs present, Intel integrated graphics and Vega, so I guess the info that it's a "K" processor is correct.
Is it known that the KF chips disable the video compressors/decompressors in addition to the main GPU?
That is the difference between the k and the kf. The kf has the igpu disabled off.
Is done so intel can sell the chips and in theory can get a higher cpu overclock the the igpu not running putting heat.
Target market for the k and kf are the game enthusiasts who will most definitely be using additional gpu card so the igpu not being present jsn’t An issue.
Yes, but - the video compression/decompression isn't really part of the iGPU. It is a whole separate block of silicon. It is conceivable that all these extra modules are still enabled in the KF parts - and only the UHD630's 24 execution units (i.e. 192 shading units) are disabled.
Zdigital2015
macrumors 601
KF CPUs do not have Intel QuickSync Video because QuickSync is dependent on the iGPU being present. KF CPU’s iGPU is there, but it is disabled. Check this URL - https://ark.intel.com/content/www/us/en/ark/search/featurefilter.html - and filter by QuickSync = YES.
https://www.extremetech.com/computi...s-dont-come-with-discounts-higher-clock-rates
[doublepost=1557865531][/doublepost]
In this case, it appears that Linus Tech Tips are wrong.
That's not definitive: Searching by QuickSync = NO returns zero Core series processors!
Everyone is assuming that "video" means "graphics" and that QuickSync therefore must be part of the iGPU. If you examine die photos for SkyLake and KabyLake, the change is an extra slice of "random" blocks in the area between the iGPU and the CPU cores. KabyLake's QuickSync supports more video modes, hence the extra slice must be the dedicated logic for the extra modes. (Well, I suppose the extra slice could be even more dark silicon for Google, the NSA, Amazon AWS, or whomever...)
So I reiterate: Has anyone definitively proven that QuickSync cannot be used on KF series chips? Ignore press releases, pundit assumptions, and OS enumerations of available features. What happens when a driver attempts to use QuickSync on a KF chip? Quite possibly this experiment needs to be done in Linux.
https://ark.intel.com/content/www/u...9900k-processor-16m-cache-up-to-5-00-ghz.html
Intel page for i9 9900k lists quicksync
https://ark.intel.com/content/www/u...900kf-processor-16m-cache-up-to-5-00-ghz.html
Intel page for i9 9900kf does not list quicksync at all. Is why quicksync = no doesn’t return any as either lists or doesn’t mention quicksync full stop.
What more does anyone need. These aren’t marketing releases etc but the vendors specification pages for the cpu’s.
Intel page for i9 9900k lists quicksync
https://ark.intel.com/content/www/u...900kf-processor-16m-cache-up-to-5-00-ghz.html
Intel page for i9 9900kf does not list quicksync at all. Is why quicksync = no doesn’t return any as either lists or doesn’t mention quicksync full stop.
What more does anyone need. These aren’t marketing releases etc but the vendors specification pages for the cpu’s.
Zdigital2015
macrumors 601
Because the desire to believe Apple is screwing its users seems to defy common sense or reason...there is zero evidence that Apple is using KF CPUs and while I respect Linus and LTT, him saying it doesn’t make it so...KF CPUs actually cost more at retail, which should be reason enough for anyone to not worry that Apple is using them...but I digress.
The standard System Information indicates that the USB-A ports are limited to 5 Gbps. My guess is that they are USB 3 (not the very similar USB 3.1 gen1) just like in the 2017 iMac but I don't know how to tell the difference or whether it matters.
My Samsung T5 is connected via one of the USB-C/TB ports.
So just to confirm, in system profiler it shows a link speed of 5Gbps when the T5 is connected to a USB A port and a link speed of 10Gbps when the T5 is connected via the USB-C/TB port?
Bohemien
macrumors regular
Just FYI: In this video, besides testing the Vega 48 vs. the 580X, Max addresses the "KF or K" confusion and shows several diagnostics tools saying it's a K CPU and QuickSync is available (go to 1:58 for this part).
Kay at work
macrumors newbie
Hello guys! Im from Russia, but live in Greece!
I wanna tell u, that we entangled too. In our store in Greece
I5 9600 indicate as KF(screenshot below).
Also another store in europe indicate the same!
And macobserver.com told about KF too.
I saw you mentioned video review by Max Yuriev. If we go to 1.20 we see how lagged 4k video. Why? If u saw review on iMac 2017 - there we will not see such. Video smooth. I think it is because we dont have iGpu there. Direct dependency as i know. Hmm... or we never didnt see playback in fcpx 10bit on 2017 i5 7600k and 580 and? Is it so bad? I dont belive 🙂)))
If somebody know where we can see workflow in fcpx in 4K (timeline in better quality) on iMac with i5 9600 K or KF pleeeeeaaaseeeee.....show me!! I counted on i5 - i9 out of my budget. Thanx a lot!!!
And... somebody know how i can change my name?!?! I made a mistake, im Kay AT work... sent message to admin.
I wanna tell u, that we entangled too. In our store in Greece
I5 9600 indicate as KF(screenshot below).
Also another store in europe indicate the same!
And macobserver.com told about KF too.
I saw you mentioned video review by Max Yuriev. If we go to 1.20 we see how lagged 4k video. Why? If u saw review on iMac 2017 - there we will not see such. Video smooth. I think it is because we dont have iGpu there. Direct dependency as i know. Hmm... or we never didnt see playback in fcpx 10bit on 2017 i5 7600k and 580 and? Is it so bad? I dont belive 🙂)))
If somebody know where we can see workflow in fcpx in 4K (timeline in better quality) on iMac with i5 9600 K or KF pleeeeeaaaseeeee.....show me!! I counted on i5 - i9 out of my budget. Thanx a lot!!!
And... somebody know how i can change my name?!?! I made a mistake, im Kay AT work... sent message to admin.
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Kay at work
macrumors newbie
I want to add a bit information from website Appleinsider Russia.
They are write about KF cpu in new iMacs!
This is original link on this page, u can use translater in chrome
They are confirm than MODEL OF CPU IS "K"
I think thats why CpuID show "K" and "F" its just version of K model.
On another russian website they are write KF processors are more expensive than analog K with a working GPU because the exclusion of the integrated graphics core will increase the clock frequency and provide the best overclocking potential in models with an index K!
They are write about KF cpu in new iMacs!
This is original link on this page, u can use translater in chrome
They are confirm than MODEL OF CPU IS "K"
I think thats why CpuID show "K" and "F" its just version of K model.
On another russian website they are write KF processors are more expensive than analog K with a working GPU because the exclusion of the integrated graphics core will increase the clock frequency and provide the best overclocking potential in models with an index K!
Kay at work
macrumors newbie
This is the one I meant to post.
In all seriousness, the fact that CPU-Z picks up the KF designation strongly implies that CPU-Z could be used to identify imacs with the KF part.
Can we really trust Linux Tech Tips?
Its true? KF inside iMac 27'? I am a bit matted in screenshots
Kay at work
macrumors newbie
Agilato
macrumors newbie
I installed i9-9900KF in my system about 3 months ago and have no issues (at least with what i use)
My other PC has i9-9900K CPU and i can replace it right now. But don't want to do unnecessary job.
What's why I decide to test iMac before gluing it back.
Any suggestions for testing?
My other PC has i9-9900K CPU and i can replace it right now. But don't want to do unnecessary job.
What's why I decide to test iMac before gluing it back.
Any suggestions for testing?
GCtravellerguy
macrumors newbie
Hi mate any issues you’ve found fitting the i9 9900KF in iMac as I’m able to get one $200 cheaper than a 9900K here currently