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igilphoto

macrumors member
Original poster
Nov 2, 2018
36
28
Hey guys , quick question for you and would love to hear your thoughts.

I'm going to get a new iMac now they finally got an update ,and I'm only can't decide between the graphics card .
The 27 inch model with 575x costs the same as the 580x and all the other specs are the same .
It looks like no brainer but I don't really need that extra power and I'm afraid that the mac will be much more louder and will get hotter .
I heard that in the 2017 models the option with older 580 was considered louder and hotter .

What are your thoughts ? They still aren't out so its only speculation but what do you think?
 

Voyageur

macrumors 6502
Mar 22, 2019
259
241
Moscow, Russia
Hello! The letter X in Radeon cards means factory overclocking and there are no exact tests for new iMac video cards, in my opinion, we can be guided right now by the difference between usual 575 and 580 Radeon graphic cards from the previous generation iMac.
According to numerous tests, between them there is a difference of about 15% performance in favor of 580. In addition, it has twice as much memory. But on the other hand, TDP in 575 is 120W, while 150W is required in 580. This can have a negative effect on temperature and noise.

As a result, if you really do not need an increase in graphics power, then you will save your money and, most likely, your computer will be heated and make noise less likely.

But in order to know for sure, we need to see the tests of this graphic cards themselves and wait for the teardown of the new iMacs
 

igilphoto

macrumors member
Original poster
Nov 2, 2018
36
28
Hello! The letter X in Radeon cards means factory overclocking and there are no exact tests for new iMac video cards, in my opinion, we can be guided right now by the difference between usual 575 and 580 Radeon graphic cards from the previous generation iMac.
According to numerous tests, between them there is a difference of about 15% performance in favor of 580. In addition, it has twice as much memory. But on the other hand, TDP in 575 is 120W, while 150W is required in 580. This can have a negative effect on temperature and noise.

As a result, if you really do not need an increase in graphics power, then you will save your money and, most likely, your computer will be heated and make noise less likely.

But in order to know for sure, we need to see the tests of this graphic cards themselves and wait for the teardown of the new iMacs

Thank you for the detailed answer !
Thats actually what I'm doing , trying to decide based on the last models .Right now I'm leaning towards the 575 .

By the way ,they're actually cost the same for some reason .You can in see in the configuration pricing .
 

Voyageur

macrumors 6502
Mar 22, 2019
259
241
Moscow, Russia
Thank you for the detailed answer !
Thats actually what I'm doing , trying to decide based on the last models .Right now I'm leaning towards the 575 .

By the way ,they're actually cost the same for some reason .You can in see in the configuration pricing .
Well, that's funny! In my country there are still no prices for new custom iMacs, so I did not notice that the price is the same until I entered the US store segment.

In my opinion, this increases the choice of 580X, because for the same money, you get more power, which will be enough for a little longer time, and if you don’t heavily load the system with graphics (you don’t initially have such tasks), it’s possible the computer will not be heated?
 

CWallace

macrumors G5
Aug 17, 2007
12,095
10,846
Seattle, WA
Even though the 580 has a higher TDP than the 575, if you are not stressing it, then it's not going to be using anywhere near that power and therefore will run cooler and the fan will not need to spin as fast and loud.

So if you can get the 580 for the same price and spec as the 575, why not? If you never need the power, you won't see the heat or fan noise and if there are times you do need it, well you have it.
 

Abbas

macrumors regular
Jul 9, 2008
176
48
Dubai
Wouldn't the argument here be that because the 575 doesn't have as much headroom, it won't ever hit as high temps and fan speeds no matter what the OP is doing. So for example, if they are encoding in FCPX, both the 580 and the 575 would be pushed to its max but since the 580 can go higher, the fans will kick in versus the 575


Even though the 580 has a higher TDP than the 575, if you are not stressing it, then it's not going to be using anywhere near that power and therefore will run cooler and the fan will not need to spin as fast and loud.

So if you can get the 580 for the same price and spec as the 575, why not? If you never need the power, you won't see the heat or fan noise and if there are times you do need it, well you have it.
 

CWallace

macrumors G5
Aug 17, 2007
12,095
10,846
Seattle, WA
Wouldn't the argument here be that because the 575 doesn't have as much headroom, it won't ever hit as high temps and fan speeds no matter what the OP is doing. So for example, if they are encoding in FCPX, both the 580 and the 575 would be pushed to its max but since the 580 can go higher, the fans will kick in versus the 575

Yes, but going from the original post, it sounds like they won't normally be performing tasks that will stress the GPU. So the 580 should normally run "slow" enough that it does not generate much heat. But if they do have the occasional task that will stress the GPU, the 580 will perform it quicker, though it will generate more noise doing it.

My 580 is around 45°C right now and I hear no fan noise (fans are at 1100RPM). If I stress it, it will hit 80° and then I will start to hear fan noise as they ramp up to their 2700RPM maximum. As I rarely stress my GPU, however, I do not hear fan noise most of the time. But I do appreciate the extra performance when I need it and I accept I will hear fan noise for a time.

They key phrase for me is they said they pay the same for the 575 or the 580. If they had to pay more for the 580, then I would probably recommend them stay with the 575 to save the money.
 

mikehalloran

macrumors 68020
Oct 14, 2018
2,238
665
The Sillie Con Valley
You will read post after post after post on how hot/loud the i7 iMacs are. Most are written by people who neither own nor have any hands-on experience with them. Neither do these “well, I read somewhere” reports tell the whole story.

I have removed the HDDs in a large number of i7 iMacs (both HDD & Fusion) over the years and replaced them with SSDs. The universal report is that this makes them run much cooler and quieter while making them faster and capable of increased workloads. Same as it did with mine.

The work you do on it will have the biggest impact providing that you avoid Fusion drives to begin with. Serious gaming will make them run hot—very few other tasks will do so.
 
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igilphoto

macrumors member
Original poster
Nov 2, 2018
36
28
Thank you for the detailed replies !
I'm a photographer so I don't think I will stress the mac too much ,mostly maybe when exporting images from Lightroom or different editing tasks .
Right now I have an old 2011 iMac and while its working ,the fans gone crazy so its making a lot of noise .
That is why I think I'm so scared buying a new machine and then hear noise all the time again .

But after reading your thoughts it seems that I'm overthinking it and should get the 580 .
 

kaintxu

macrumors regular
Jul 9, 2018
196
76
Edinburgh
Hey guys , quick question for you and would love to hear your thoughts.

I'm going to get a new iMac now they finally got an update ,and I'm only can't decide between the graphics card .
The 27 inch model with 575x costs the same as the 580x and all the other specs are the same .
It looks like no brainer but I don't really need that extra power and I'm afraid that the mac will be much more louder and will get hotter .
I heard that in the 2017 models the option with older 580 was considered louder and hotter .

What are your thoughts ? They still aren't out so its only speculation but what do you think?

Sorry but where does it say the 575 and the 580 models cost the same? And not all the other specs are the same, the 575 comex with an 8th gen i5 while the 580 has a 9th gen i5
 

Voyageur

macrumors 6502
Mar 22, 2019
259
241
Moscow, Russia
Sorry but where does it say the 575 and the 580 models cost the same? And not all the other specs are the same, the 575 comex with an 8th gen i5 while the 580 has a 9th gen i5
If we choose the middle and top (the model on the right) options for customization, choose an i9 processor and 2TB Fusion Drive for each, then they both will cost $ 2,699. The average will be with 575X, and the top right with 580X graphics
 

igilphoto

macrumors member
Original poster
Nov 2, 2018
36
28
Thank you !
I'm actually now having second thoughts about the i9 but at least decided on the graphics
 

nihil0

macrumors 6502
May 19, 2016
456
373
I think you should go for 580X because if you want to customize your iMac (different CPU or larger fusion/SSD drive), you will get to almost same price but you will have 4 GB VRAM less on 575X model. It only makes sense to keep 575X model when you will stay on basic config. And there you are saving money again on storage and CPU and not on GPU.
 

kaintxu

macrumors regular
Jul 9, 2018
196
76
Edinburgh
I bought the Core i5/580x model and it is QUIET! Even when running the Unigen benchmark, I could not hear the fans at all.

Can you run some Unigen heaven benchmarks? I have seem some results for the i9 with vega, but none for the I5 with 580X. If you could do it on OS X and if you have boot camp on windows, that would be great.

Cheers
 
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