Author Topic: Building a PC, what CPU?  (Read 775 times)

fuaran

  • rothair gasta
Building a PC, what CPU?
« on: November 28, 2018, 01:38:02 pm »
I'm planning on building a new PC. I want a fairly small case, so it will probably be based on a Shuttle XPC cube barebones. Probably a Shuttle SH370R6.

It uses Socket 1151 Intel CPUs. It supports 8th and 9th gen Intel CPUs, but 9th gen requires a BIOS update. So may need to buy/borrow another (8th gen) CPU first, to do the update.

Anyway, what CPU to get? Will be used for the usual stuff, web, bit of photo editing, occasional video editing, maybe a bit of light gaming.
Core i3, i5, or i7? Is there much difference between them? I know i5/i7 is faster and more cores, but do you actually notice much difference, other than gaming?

Is it worth paying £200 more for a better CPU? Any bargains around?
Is there much improvement with 9th gen? Seems they have finally done a proper fix for Spectre/Meltdown.

And is there much difference in power consumption between them? Would like to save electricity where possible, and less cooling required.

Re: Building a PC, what CPU?
« Reply #1 on: November 28, 2018, 01:56:36 pm »
Not precisely the question you asked, but I was just looking to see if there was a meaningful, economical, upgrade possible for my 4+ years old 3.2Ghz Quad core i5, my conclusion was that there wasn't, and that a decent i5 is the sweet spot of price/performance for Intel. Combine it with some decent RAM and an SSD and you have a good start. Oh, and YES, you do notice the difference between i3 - i5. i5 to i7, less IMO.

Talking of RAM if you (or anyone else) could use 2 x DIMM - Corsair Vengeance 4gb=8GB, PC3-12800 (DDR3-1600), it's going for nuffink. I bought this to add to my existing 16Gb and it just reboots without ever getting to the BIOS. RAM is probably ok, just some mismatch with what I have in, and I CBA to mess around, can't sell it as working so I'll have to write it off to experience. Specs are the same as the 2 x 8Gb I have in, so I assume it needs to be all the same size or summat.

ETA - of course it all depends on what you use it for. Mine's principal loading is for VM and graphics, no gaming.

Re: Building a PC, what CPU?
« Reply #2 on: November 28, 2018, 02:26:14 pm »
I've been thinking about a new machine for Lightroom/photoshop and concluded that a fast i5 (8600k @ 3.6GHz) was probably about the sweetspot.

Re: Building a PC, what CPU?
« Reply #3 on: November 28, 2018, 03:44:43 pm »
I just ran a benchmark of my processor (i5-4690, 4 core, 4 thread) @ 3.5Ghz using CPU-Z, compared to a i9-9900 @ 3.6Ghz (8 core, 16 thread).

Single core benchmark 409 vs 580, multi thread 1460 vs 5903. given that mine is 5 generations and 3 levels downversion, that's not that shabby. the gains are incremental not quantum.

So, it seems performance gains are to be had from the cores/threads (as long as your software supports) and IO (mine's SATA/PCI Express) and a reasonably selected processors can hold its own for longer than you might have thought a while ago.

CPU-Z benchmarks can be found here https://valid.x86.fr/bench/1

Re: Building a PC, what CPU?
« Reply #4 on: November 29, 2018, 12:54:48 am »
I've been thinking about a new machine for Lightroom/photoshop and concluded that a fast i5 (8600k @ 3.6GHz) was probably about the sweetspot.

But I continue to be amazed at the ongoing utility of my Lenovo W530 laptop/mobile workstation. It’s got an i7 3740qm with 4 cores, threads and is clocked at 2.7GHz base. It seems to skip up to 3.6GHz when it thinks turbo mode is needed with only a speed up of the game to let you know it’s working.

The machine has 32Gb of ram and 3 ssd’s. It’s currently updating adobe creative cloud with a nice solid download speed of 71Mbps and the cpu isn’t really doing more than tick over apart from when it needs to shift the data around. The GPU will do a bit of work rendering big files in Lightroom or playing 4K videos on the Tacx trainer.

It ought, if you believed the press, to be obsolete by now, but it still works OK.

Re: Building a PC, what CPU?
« Reply #5 on: November 29, 2018, 11:03:37 am »
I've been thinking about a new machine for Lightroom/photoshop and concluded that a fast i5 (8600k @ 3.6GHz) was probably about the sweetspot.
It's six years since I built my current PC with an i5 4670K, so I have no idea about the current options.  For the only time since my first computer I have no desire to upgrade.
I have used Lightroom on several systems, mine and for work, it doesn't seem to make much difference what CPU, but plenty of memory can transform it.

Woofage

  • Ain't no hooves on my bike.
Re: Building a PC, what CPU?
« Reply #6 on: November 29, 2018, 11:21:29 am »
Woofage Junior has an old computer of mine with a 2nd gen i5 quad core. With a reasonable graphics card, 16GB RAM and an SSD it chugs along very nicely. He plays games on it and edits photos etc. If he was dissatisfied with its performance I'm sure he'd soon say so.

Conclusion: don't sweat too much about the cpu. Just get a decent i5 and it will be fine for several years. Do take a look at the TDP figures though to give you a comparison of power consumption.
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Mr Larrington

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Re: Building a PC, what CPU?
« Reply #7 on: November 29, 2018, 02:19:24 pm »
Video manipulation is one of the few things that will cause a modern "desktop" PC to break out of a canter.  Well, that and rebuilding ultra-compressed .zip archives of ridiculous size.
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tonycollinet

  • No Longer a western province of Númenor
Re: Building a PC, what CPU?
« Reply #8 on: November 29, 2018, 06:29:52 pm »
I built a new PC in August and fitted the fastest processor I could (was prepared to) afford. Paid £300 for an I7 8700K - but that has gone up almost £100 since. Hackintoshed it.

Generally feels quite a bit snappier than my mobile I7 equipped macbook air which was my previous all round machine.

I really notice the difference with photo editing. Generally it is again much smoother and I don't really notice wating for stuff any more. But especially with exporting from Lightroom to external programs such as Luminar or HDR Efex (especially this as it exports 5 pics for one HDR).

I use this list to get an idea of what the different CPU's will feel like relative to one another.
https://www.cpubenchmark.net/cpu_list.php


EDIT: As above - I wanted a fast CPU to be good for video, but I've not done much of that yet.

Re: Building a PC, what CPU?
« Reply #9 on: November 29, 2018, 06:44:16 pm »
Video manipulation is one of the few things that will cause a modern "desktop" PC to break out of a canter.  Well, that and rebuilding ultra-compressed .zip archives of ridiculous size.

Running several VMs using VMware player or Virtualbox will do it as well. Or running 16 or so virtualised routers in GNS3.

In practice you are correct for normal desktop applications only video editing and cutting edge games stresses a CPU.
I think you'll find it's a bit more complicated than that.

Re: Building a PC, what CPU?
« Reply #10 on: November 29, 2018, 07:09:38 pm »
I was given an old i5 based server from work to make a gaming PC for my son.

We put 20 something gb of server RAM into it (so not especially fast RAM) and then threw in a massive fancy graphics card and a new monitor and it runs like a dream.

So much so that I want more RAM for the home computer now...

Re: Building a PC, what CPU?
« Reply #11 on: November 29, 2018, 07:25:54 pm »
For most thing I do Lightroom and photoshop don’t actually need much more than a sensiblly large amount of ram and, ideally, ssd’s. I have one ssd set as the Lightroom cache disk, one is for the OS and programs and a bigger one for data that is ‘current’ and not yet archived to the NAS. The old graphics card deals with rendering perfectly well with not too many moments of delay once files are opened.

The only thing I use that really crunches the cpu is merge to panorama with multiple 36Mp files.

fuaran

  • rothair gasta
Re: Building a PC, what CPU?
« Reply #12 on: November 30, 2018, 02:30:09 am »
Thanks, an i5 looks like a reasonable option.
Looks like the i5 8600K and i5 9600K are now about the same price (£250). So probably worth going for the newer, faster model (if the motherboard supports it).

Checking the TDP numbers, it seems most models are rated at 95W. But presumably in typical use, it would be much less than that. Or there is low power 'T' models rated at 35W, but they are a bit slower and more expensive.