Folding Forum

Alas, my 27” late 2009 iMac has died after running 24/7/365 for nine years!

I’m in the market for a new 27” iMac and am wondering which current processor, configuration and specification would be most advantageous for F@H.

Clearly I am not going to base my selection solely for the benefit of F@H but it may help me decide between models shortlisted for other considerations.

I5 or i7? Fusion drive? Other considerations?

Any advice would be much appreciated and, for the purposes of this discussion only, price is not yet a consideration (my bank manager might not agree!).

I don't have an iMac but if you can setup with dual boot for Linux then it would be possible to run FAH on a fast nvidia/amd GPU which gives the most PPD.

To answer the question in the topic : none. Get yourself a good home made PC, it will cost less for the same hardware, or you'll get better hardware at the same price.

I've been trying to convince FAH to support GPUs on Macs but so far have been unsuccessful. Part of the reason is that there are so few Macs that actually have a discrete add-on GPU (ATI or nVidia). I'm sure they'll never support the Intel iGPU. If you are ABSOLUTELY convinced that you want a Mac (contrary to toTOW's advice, which I do support) get one that accepts add-on GPUs, just hoping that I might someday succeed.

Some advice here applies if you were getting a computer just for folding, but as I recall you used your iMac for your personal computing needs and ran folding the rest of the time. With that in mind, based on using my iMac in a similar manner here are my suggestions:

My experience with the most recent CPU folding core, A7, while it gets a bit more performance from the HT cores of an i7 it is not as much as for the older A4 folding core. But the HT cores can handle processing for other software processes lessening their impact on folding. So if you can afford it, go for the i7. and just run folding on the main cores of the CPU. If not , the i5 will be more than adequate.

The drive is of less significance, get one that is large enough to support your needs. Though I understand that the 2 TB and larger Fusion drives are somewhat faster than the 1 TB drive.

The base amount of RAM at 8 GB is also enough for folding, but you may want to double that. If you buy a 27" iMac at least the RAM is user upgradable if you start with the 8 GB model and costs half what Apple will charge you.

To give you an idea,
I installed a 22nm, 2014, $50, 10 core - 20 thread server CPU, running at 1,8-2Ghz, about 2-3 weeks ago.
I basically installed a GTX 1050 in it, (and a 1030, but that's beside the point, as it really doesn't accumulate to much).
The GTX 1050 was $120.
The CPU was $50. Motherboard was $100, PSU was $50, and case was $80, and a $35 128GB SSD.
Equals $435 (+ a $100 Windows operating system I didn't need, as I easily could run a free version of Linux).

I mean, if it's for folding only, what better than a streamlined OS, you only need to interface with during installation and occasionally booting the FAH control program?
Aside from folding, it works also well for any day to day activities, like browsing, mails, steam gaming, and work.


The GTX 1050 (graphics card) is about 3-5x faster than my CPU.
And my CPU is about 3x faster than most modern Corei5's around here, as it's a server CPU, not a desktop CPU.

In 2 weeks time, and at now just over 2M PPD, I became within the top 2% of folders on the FAH website, with what others would consider a 'modern, mid grade' graphics card.
I could have gotten this in 1 day, had I purchased the RTX 2080 card, but I didn't know, nor had the extra cash.

I did understand, that I needed a more powerful card, so I added a 1060, and an RTX 2070 is on the way as third card.
Running this configuration will get me in the top 1% of FAH, PPD wise, in the next week, as I'll double my PPDs now within 2 days, and again 4 days after that!

The cost you've paid on electricity doesn't justify the results.
You could have purchased yourself a nice GTX 1080 or RTX 2080 card by now for the electricity used, and run them for only 2-3 days straight, and have more work done, than the old iMac could in 9 years.
That is, the Imac would probably get 4-5k PPD max at 200Watts usage.
An RTX2070 with dual or quadcore CPU would get you about +1M PPD, at 200Watts.

In other words, get a cheap PC case, a motherboard with 1 or 2 PCIE 16x slots, LGA1151 CPU, they cost about $50 for the motherboard, $30 for the case, $25-$50 for the CPU, and $50 for an 80% bronze PSU.
That's a folding machine for under $200, + graphics card.
Linux is free; there are even linux versions that look like IOS...