i7-7700 or i7-7700K
 

I am building a new rig and will order one of these in two days. I know the "K" has an unlocked clock. Based on what I have studied in the past few weeks, they both can multi-thread. Would I run the K clock above the base? Probably, but not much. It would depend on the heat output.

There seems to be two supporting chipsets. B250 and Z270. The 7700 could be placed on a B250 main board. The 7700K would be better on a Z270. I normally run Prime95 doing P-1 work all the time [U]and[/U] [I]mfaktc[/I] or [I]CuLu[/I] doing whatever I choose at any given time. I've never had an issue with running CPU and GPU concurrently.

I am open to suggestions, observations, and whatever else anyone has to offer...

I am running my 3.5GHz 4770k rock solidly at 4.2GHz. How? I bought and fitted a cheap AIO water cooling system. :smile:

The Z motherboard lets you overclock memory. The B does not. Since prime95 will be bottlenecked by memory with that CPU, I'd go with the Z and some DDR4-3200 (or whatever the sweet spot is right now).

Though I have no personal experience, several have reported benefits from dual-rank memory. You'll need to do some digging to figure out if memory is dual rank -- the info is not easily accessible.

If money is tight and the Z with 7700K and DDR4-3200 does not fit the budget, then I'd drop down to a i5-7500 with dual-rank memory.

Also: get a platinum power supply. IMO it will pay for itself.

[QUOTE=Prime95;460088]If money is tight and the Z with 7700K and DDR4-3200 does not fit the budget, then I'd drop down to a i5-7500 with dual-rank memory.

Also: get a platinum power supply. IMO it will pay for itself.[/QUOTE]

As I wrote, I have looked at a lot of boards. They all were sub-DDR4-3000. I've seen several brands: MSI has, by far, the most offerings. I'll have to check them all again. I found a single 16GB Corsair DDR4-3200 module. Perhaps a good place to start.

I have an NVidia GTX-480 here sealed in a box. I plan to run it for a while, but not indefinitely. The platinum PSU's I looked at are all 750W and that's fine. I considered going that high a few weeks ago while I was picking parts. That's no big deal. The one I looked at was a Gold EVGA. The Platinum's I just looked are also EVGA. 10 year warranty on each.

What about an i5-7600K? It's a $100 bill off the 7700K. :smile:

[QUOTE=storm5510;460105]What about an i5-7600K? It's a $100 bill off the 7700K. :smile:[/QUOTE]

You really do want dual rank memory. You'll get about a 10% performance boost. Many (all?) 16 GB DDR4 sticks are currently dual rank. From what I've observed it matters more than using slightly faster clocked memory. It seems dual rank memory can fetch and store memory faster since it is interleaved across more chips. Dual rank modules will almost certainly have chips on both sides of the PCB. CAS latencies, etc., don't matter.

My Skylake cores at 3.3 GHz saturate DDR4-2133 dual rank. The 7600K at stock 3.8 GHz would be alright with DDR4-2400 or 2666, but if you ran at its turbo of 4.2 GHz, 2666 or 2800 MHz would be better. 2/3rds of 7600K can overclock to 4.9 GHz, which would suggest using DDR4-3200.

The 7600 clocks slightly lower, and it supports DDR4-2400 on a non-Z (inexpensive) motherboard.

If you're using this machine for other purposes beside this project, I would highly recommend going with the 7700 (non-Z, DDR4-2400) or 7700k (Z, DDR4-3200). Hyperthreading isn't useful for Prime95, but it will extend the longevity of your system as games and applications are becoming increasingly multi-threaded.

All that boils down to these recommendations to pick from based on budget:

7700K + 2 x 16 GB DDR4-3200 + Z motherboard (general purpose)
7700 + 2 x 16 GB DDR4-2400 + non-Z motherboard (general purpose)
7600K + 2 x 16 GB DDR4-3200 + Z motherboard (prime things only)
7600 + 2 x 16 GB DDR4-2400 + non-Z motherboard (prime things only)

And as George said, you [i]really[/i] want at least a Gold rated power supply. It will pay for itself in about a year from saved electricity. Platinum is better, but will take a couple years to pay off.

Your GTX 480 is getting long in the tooth. A GTX 1060 will pay for itself in electricity savings in one year (at 15¢/kWh) giving slightly better TF performance. It wouldn't be as fast for CuLu though.

[QUOTE=Mark Rose;460110]... The 7600K at stock 3.8 GHz would be alright with DDR4-2400 or 2666, but if you ran at its turbo of 4.2 GHz, 2666 or 2800 MHz would be better. 2/3rds of 7600K can overclock to 4.9 GHz, which would suggest using DDR4-3200.

The 7600 clocks slightly lower, and it supports DDR4-2400 on a non-Z (inexpensive) motherboard.

If you're using this machine for other purposes beside this project, I would highly recommend going with the 7700 (non-Z, DDR4-2400) or 7700k (Z, DDR4-3200). Hyperthreading isn't useful for Prime95, but it will extend the longevity of your system as games and applications are becoming increasingly multi-threaded...[/QUOTE]

I'm not a gamer, so that solves that. As you say, the 7600K bases at 3.8 GHZ and can run up to 4.2 GHz. The i5-3570 I have now bases at 3.4 GHz and runs up to 3.57 under any type of load. It changes on its own.

I've picked a Z270 board that can handle up to DDR4-3800. It supports any Gen 6/Gen 7 CPU. George recommended a Z270; something about a memory bottleneck with a non-Z.

I have also picked a 750W Gold standard PSU. I leaned a hard lesson with this HP workstation. I have a GTX-750 Ti in it and the PSU can't supply what this adapter really needs. I'll not be caught short again.

The GTX-480 is PCIe-2, and yes, it is approaching the obsolete point. Still, I paid $40 for it. Some are still selling for ten times that, used. I've looked at some 1060's, and even 1080's. The 1080's are out of my budget range, for now.

I never intended to build this in a single shot. I just can't do it. I have to stretch it out over time, but that time is limited. I'm having a lot of hip-joint issues caused by decades of walking/standing on concrete floors. I'm going to have to retire at 62. That's in October. I plan to get out in mid September, if my legs can hold up until then.

[QUOTE=Mark Rose;460110]7700K + 2 x 16 GB DDR4-3200 + Z motherboard (general purpose)
7700 + 2 x 16 GB DDR4-2400 + non-Z motherboard (general purpose)
7600K + 2 x 16 GB DDR4-3200 + Z motherboard (prime things only)
7600 + 2 x 16 GB DDR4-2400 + non-Z motherboard (prime things only)[/QUOTE]

I'm going to attempt to land in the middle of this, if it's possible. I have some thinking to do...

[QUOTE=storm5510;460119]I'm not a gamer, so that solves that.[/quote]

Hyperthreading is still useful though. My desktop at work is a 4770K, with hyperthreading enabled. I hardly notice Prime95 running. My desktop at home is a 6600 and it's easy to tell when Prime95 is running (it's not quite as responsive). There's always background tasks running with modern operating systems.

[quote]As you say, the 7600K bases at 3.8 GHZ and can run up to 4.2 GHz. The i5-3570 I have now bases at 3.4 GHz and runs up to 3.57 under any type of load. It changes on its own.[/quote]

The biggest difference you'll see is from FMA3 in the 4xxx and later chips. The i5-7600 would be 50%+ faster at LL than your i5-3570, if equipped with DDR4-2400.

[quote]
I've picked a Z270 board that can handle up to DDR4-3800. It supports any Gen 6/Gen 7 CPU. George recommended a Z270; something about a memory bottleneck with a non-Z.[/quote]

In the DDR3 days, the 1600 MHz limit on the non-Z boards was a severe bottleneck, especially with the 4-core 4xxx series. The limit on the B250/Q250/Q270/H270 motherboards is 2400 MHz, which is much better balanced with a 4 core, non-overclocked CPU. I would only get a Z270 motherboard if you plan to get a CPU that supports overclocking and to overclock it and to get high speed memory. Otherwise it's just a waste of money (unless there are other features that you want on the board).

If you're trying to save some cash, I'd get a 7700 and a non-Z motherboard with DDR4-2400. Something like [url=https://pcpartpicker.com/list/xhfv7h]this[/url]. Maybe not those exact components, but you get the idea. The hyperthreading and lots of RAM should give you lots of life out of the machine (without replacing components in the future) and it's balanced for Prime95 usage.

[quote]
The GTX-480 is PCIe-2, and yes, it is approaching the obsolete point. Still, I paid $40 for it. Some are still selling for ten times that, used. I've looked at some 1060's, and even 1080's. The 1080's are out of my budget range, for now.

I never intended to build this in a single shot. I just can't do it. I have to stretch it out over time, but that time is limited. I'm having a lot of hip-joint issues caused by decades of walking/standing on concrete floors. I'm going to have to retire at 62. That's in October. I plan to get out in mid September, if my legs can hold up until then.[/quote]

The graphics card can always wait :smile:

[QUOTE=Mark Rose;460124]If you're trying to save some cash, I'd get a 7700 and a non-Z motherboard with DDR4-2400. Something like [url=https://pcpartpicker.com/list/xhfv7h]this[/url]. Maybe not those exact components, but you get the idea. The hyperthreading and lots of RAM should give you lots of life out of the machine (without replacing components in the future) and it's balanced for Prime95 usage.
[/QUOTE]

I believe you are correct. I considered a 7700 for a while. It's not quite as pricey as the 7700K. I looked at some B250 boards; most are MSI.

What about a cooler for the CPU? I've looked at lots of them.

[I]Thank you for picking your own brain for me.[/I] :smile:

[QUOTE=storm5510;460125]I believe you are correct. I considered a 7700 for a while. It's not quite as pricey as the 7700K. I looked at some B250 boards; most are MSI.

What about a cooler for the CPU? I've looked at lots of them.

[I]Thank you for picking your own brain for me.[/I] :smile:[/QUOTE]

I suggest the Arctic Freezer i11. I'm using 10 of them on various systems. Its fan is quiet and has a fluid-dynamic bearing that won't wear out for a long time. It's inexpensive and will fit in most cases. Most other <$25 coolers have cheap fans that will die in a year.