Newest iMac i5 top spec quiet?

[gryphongryph]

Hi guys, first here is my stereo. MacBook Pro 2008 + ext hd + Roon

Intona usb isolator 

Primare Dac30

DK Design VS.1 Reference MK2 Hybrid integrated amp with Nos Mullard’s in pre section 

Graham Audio LS 5/9 speakers.

 

I would like to buy a iMac i5 to use as a photo editor and install Roon on it, so combining it with my stereo in the same room, plan is to use the Ethernet connection to a Pro-Ject Stream Box S2 Ultra, then usb into my dac 30, my question is, is the iMac totally quiet running Roon ?

my 2009 IMac is quite noisy  and the computer will probably be situated a meter behind me!

hope for some input.

 

 

 

[gryphongryph]

No one using a iMac i5 for Roon streaming?

[AudioDoctor]

I can't imagine why it wouldn't be. I have an iMac a year old, but basically the same thing considering it has not yet been updated, and I ran ROON on it without any problems, and I was using my computer as the player as well, I wasn't streaming to anything. Fans never came on.

[gryphongryph]

Nice to know, my old iMac sounds more like a boiler that a fan blowing, but one can hear it easily!

[AudioDoctor]

Yeah, I have a 2011 Mini around here and ROON would get the fans running full blast.

[Ralf11]

iMac Pro has much improved ventilation, so may have the quietest acoustic signature - for $$$

 

I suspect most people getting any iMac are going i7

[gryphongryph]

I heard that the i7 iMac is quite noisy, that’s why I am more interested in the i5, the Pro is a bit too expensive and more than I would need. I am just a amateur photographer 😉

[AudioDoctor]

I dont know who told you that, I have the i7 and its as quiet as a church mouse.

[Ralf11]

maybe based on the notion that more power ==> more noise ??

 

my 2017 i7 (40 G RAM 3TB Fusion) is very quiet until I do something like an HDR build in LR etc.

 

- Roon might light it up?

[gryphongryph]

Lol, maybe, have just read on a lot of forums that the i7 can be a bit noisy, but the i5 is much quieter, but nice to hear differently, you guys use it with Roon ?

[MMMSA-10]

FWIW, I use a 2018 Mac Mini i3 and a 2017 iMac i7 with Audirvana and there is no audible fan activity with either.

 

I have noticed fan activity on my iMac doing some photo edits, but using old/possibly defunct plugins from Topaz - ones like deNoise.

[Ralf11]

The way to think about this, is what sort of activity is likely to trigger the fan, and how does the architecture of the i5 vs. i7 correlate with that.

 

Anyone can post in a forum, so I'd want to see if they tested, how they tested, or if it was just speculation was it well-founded in some mechanistic way.

 

or... just get what works well for your total uses - you mention photography, so that may mean post-processing.  Adobe Lightroom (for one) goes faster with CPU speed per se, and they are NOT using their high license fees to improve parallel processing, so more cores does little for you on LR.

 

For audio, most uses are not CPU intensive.  If you are doing a lot of upsampling in the computer then an i7 may help.

[gryphongryph]

Thanks Ralf, I have always bought the highest spec Mac I can afford, so as to make it last a long time, as my iMac is 10 years now, having put a aftermarket ssd in the dvd slot 4 years ago, the machine has given me a long service without any problems, it is time to replace it and therefore have been thinking about a machine that would be very usable for Roon too.

Any opinions about the difference between usb out to dac or using the Ethernet out to a bridge into dac, would I hear a difference?

[Ralf11]

You might hear a difference depending on how much EMF noise is transmitted along the USB cable & how well your DAC deals with it.  It might depend on the type of music too.

 

The only way to be sure is to try it.

 

Wired Ethernet has transformers that reduce this noise.  Optical Ethernet eliminates it entirely, as does WiFi.  There is also a forthcoming product to further reduce any problems with wired Ethernet.

 

For USB, you could try out a Schiit Eitr or similar isolation device and see if it improves things.

 

But... speakers, room tmts., DSP, and better masters/recordings will all make much greater improvement in SQ than addons for your DAC.  I'd put a better DAC into the mix too, tho don't know what the Primare is like.

 

It sounds like you need to keep the iMac near the listening position?

[AudioDoctor]

If you are going to connect your iMac to your DAC via USB, and use it at the same time I would not use ROON, I would use Audirvana+. In my experience, doing just that, A+ blew ROON away regarding sound quality. However, if you're going to go to a network ROON device of some sort, then I am sure ROON would be just fine sounding.  ROON really didn't like being ran and played on the same computer.

 

In fact, that is the reason I did not go with ROON, It didn't work well enough in my use case to overcome what I already had, A+.

 

The best part of this is, you can try them both for yourself.

[gryphongryph]

Plan is to have the iMac on my office desk 1 meter behind my listening sofa, therefore the Ethernet cable idea 

[Ralf11]

Sure, go with that - test the UltraEthero or whatever they call it when it comes out

[Uni]

The true problem is core audio.  Somehow the sound would be easily distorted.

[tmtomh]

2 hours ago, Uni said:

The true problem is core audio.  Somehow the sound would be easily distorted.

 

Evidence or documentation for this claim?

[Ralf11]

or just toss a dart at this diagram to "pinpoint" the SQ is degraded for us, please?

 

https://developer.apple.com/library/archive/documentation/MusicAudio/Conceptual/CoreAudioOverview/WhatisCoreAudio/WhatisCoreAudio.html

[AudioDoctor]

4 hours ago, Uni said:

The true problem is core audio.  Somehow the sound would be easily distorted.

 

Or use the A+ Direct Mode which completely bypasses CoreAudio...

[Uni]

1 hour ago, tmtomh said:

 

Evidence or documentation for this claim?

 

14 minutes ago, Ralf11 said:

or just toss a dart at this diagram to "pinpoint" the SQ is degraded for us, please?

 

https://developer.apple.com/library/archive/documentation/MusicAudio/Conceptual/CoreAudioOverview/WhatisCoreAudio/WhatisCoreAudio.html

 

Great research spirit.  I have no knowledge of all these.  My experience is simply based on the SQ of audirvana direct mode.  It's possible that I am wrong.

 

On the other hand I found out that using ipad to my USB DAC sound much better than iMac.  Thanks for your url would this sentence provide any hints?

 

"Core Audio in iOS is optimized for the computing resources available in a battery-powered mobile platform. There is no API for services that must be managed very tightly by the operating system—specifically, the HAL and the I/O Kit. "

[Ralf11]

Audirvana can use DSD etc. which iTunes / HairPlay cannot.  Is that what you mean?  Or are you comparing Redbook to Redbook?

[Uni]

8 minutes ago, Ralf11 said:

Audirvana can use DSD etc. which iTunes / HairPlay cannot.  Is that what you mean?  Or are you comparing Redbook to Redbook?

 

@Ralf11 hi, not sure are you asking me.  For my case, in terms of SQ

 

Using A+

direct mode > without direct mode

 

Roon Core@NAS

iPad + USB DAC > iMac  SSD + USD DAC

 

So I am suspecting something wrong about CoreAudio.  Of course there can be other factors too.

[ferenc]

On 1/8/2019 at 9:17 PM, gryphongryph said:

Thanks Ralf, I have always bought the highest spec Mac I can afford, so as to make it last a long time, as my iMac is 10 years now, having put a aftermarket ssd in the dvd slot 4 years ago, the machine has given me a long service without any problems, it is time to replace it and therefore have been thinking about a machine that would be very usable for Roon too.

Any opinions about the difference between usb out to dac or using the Ethernet out to a bridge into dac, would I hear a difference?

 

Actually I am using a 18 core, 16 GB GPU, 64 GB RAM iMac Pro for Roon and HQplayer upconverting to 256x DSD with Poly - since - mp everything, feeding an RME ADI-2 DAC and sometimes Merging Hapi and few Dante devices as well, running Elgato EYEtv for 4 tv tuners and doing all sorts of other thing simultaneously as well through the building-in and an external Thunderbolt 3 monitor. My Roon database handling roughly 250000 tracks, 25000 albums, lots of high-res recordings from an external Lacie 48 TB Thunderbolt 3 disk array and streaming Tidal. No problem with the iMac Pro noise, sometime the LaCie is noisy, but tried to move it as far as the TB3 cables let it. OS X is the latest 10.14.3 developer beta.