i7 8700k or i7 9700k?

[Vizzik]

Short story short, i'm upgrading my girlfriends system & was wondering which is the better pick as they're both a similar price?

Does 8 cores 8 threads perform better than 6 cores 12 threads?
I was told that the 9700k runs quite a bit hotter than the 8700k, is that correct?

[Cloudy]

I vote the i7-8700K since you could get a cheaper Z370 motherboard paired with it. Either way they are both powerful CPUs.

[Arya]

At a glance I would recommend a Ryzen 7 2700X over both of them. But if I had to pick, I'd go with the elder 8700K.

Gen-9 CPUs are extremely expensive, as are the motherboards. And right now, I don't think they do enough to justify that price. They have amazing peak-performance when overclocked, but few people actually overclock them, or would even know how. And when you do, they run incredible hot and need a very expensive cooling system. At stock speeds a 2700X gets close, but costs a fraction as much.

[Monk]

In pure gaming numbers, the 2700x as good as it is, sits quite away behind the 9700k even at stock, mind you, this is also at higher than really matters fps.

If you can get a 9700k at a sane price it is faster than an 8700k both at stock and overclocked, it's also considerably cooler than a stock 8700k, that really needs to be delided to shine.

The problem arises when you try to actually find a 9700k anywhere near its msrp (the crazy markup lead me to get a 9900k instead as it was at msrp even if it cost quite a bit more lol) , the z370 and z390 boards cost about the same however for the same sort of tier board.

[Cloudy]

引用自 Wolfey：

At a glance I would recommend a Ryzen 7 2700X over both of them. But if I had to pick, I'd go with the elder 8700K.

Gen-9 CPUs are extremely expensive, as are the motherboards. And right now, I don't think they do enough to justify that price. They have amazing peak-performance when overclocked, but few people actually overclock them, or would even know how. And when you do, they run incredible hot and need a very expensive cooling system. At stock speeds a 2700X gets close, but costs a fraction as much.

2700X has 20%-25% slower single and quad core processing compaired to an i7-8700K, or even an i5-8600K which is much cheaper. If you do a lot of gaming on your PC than I suggest the i7-8700K instead.

[Vizzik]

引用自 Wolfey：

Gen-9 CPUs are extremely expensive

引用自 Monk：

If you can get a 9700k at a sane price it is faster than an 8700k both at stock and overclocked, it's also considerably cooler than a stock 8700k

Here in the UK, you can get the 9700k for the same price right now as a 8700k

She has the same motherboard as me, ASUS prime z370-a so it shouldn't be a problem as far as i'm aware.
Just needs a bios update before switching out the cpu.

Would the 8700k outshine the 9700k if they're both running at the same speed since it has more threads & hyperthreading?

[Arya]

引用自 Deadset：

Would the 8700k outshine the 9700k if they're both running at the same speed since it has more threads & hyperthreading?

I don't think you'll see a major performance difference either way, but in most places you'll find the 8700K for less. And it doesn't need a BIOS update to run on her existing board.

I also have to wonder which would come out on top thermally, since I've been hearing horror stories about overheating since Gen-9 launched. Whether that's just people new to high-end Intel being shocked at how hot they run or signs of a genuine problem, I don't know. But it's been a common theme.

My 8700K runs semi-comfortably at 4.8 GHz with a Noctua NH-D15. Although I'll be fitting a full Water-Cooling system as soon as I can.

[Vizzik]

引用自 Wolfey：

And it doesn't need a BIOS update to run on her existing board.

I also have to wonder which would come out on top thermally, since I've been hearing horror stories about overheating since Gen-9 launched.

According to Overclockers page, it says "Attention: Motherboards with Z370, H370 and B360 chipsets require a BIOS update in order to function with a 9th generation Intel Core- series CPU"

The overheating was something i was concerned about & was why i was leaning towards purchasing the 8700k instead.

[Arya]

引用自 Deadset：

The overheating was something i was concerned about & was why i was leaning towards purchasing the 8700k instead.

Any K-Series will run hot, but at stock clocks the 8700K isn't too bad. As long as you have good airflow through your case and a good-quality air cooler, you shouldn't have any trouble.

It's only under OC that it gets really hot. And annoyingly you *do* need to OC it to unlock it's true potential. By default they're clocked at 4.3 GHz Turbo with a 4.7 Ghz single-core overboost. And that's actually an underclock, they're very comfortable at 4.7 GHz across all six cores at impressively low voltages - welll under 1.3V. The only problem is heat, and they do get pretty warm.

A Noctua NH-D15 or BeQuiet Dark Rock Pro4 would be just fine, that should keep you under 65 celsius at gaming loads and under 80 at benchmark. I personally would go for a good quality AIO, preferably a Corsair Hydro running a 280 or 360 radiator. I personally use an NH-D15 and have an EK MLC-Pheonix AIO on order.

If you go the air cooling route, your case selection will be key. The heatsinks you need are enormous, and they throw a lot of heat into the case so airflow also matters.

[Monk]

Hyperthreading is worth approx 30% of an actual core, so the 6 threads of the 8700k come in behind 2 actual cores, it's the same reason that the 8600k 6 core beat out the 7700k 4 core with hyperthreading, so, the 9700k is the faster chip with 8 actual cores.

As for temps, I've had my 9900k running a quick oc at 5.2GHz at a mere 70c on a 360mm aio, so I feel temps have been somewhat exaggerated, just fit an appropriate cooler, be it a big tower cooler (nh-d15 / dark rock 3/4 etc) or a good 240mm+ aio.

[hawkeye]

Here is an interesting thread from tom's about temps. It includes a link to a second thread on temps. Apps that use AVX run hotter, the fix is to set an AVX Offset if temps are too hot. So temps should not be a problem with 9 series cpus even on air (if paired with the right components).

https://www.reddit.com/r/intel/comments/9xkfs9/i7_9700k_real_world_gaming_temperatures_on_air/

Although the 9 series will run on both z370's and z390's, gamers nexus promoted a gigabyte z390 as having solid vrm's in its recent video on walmart psus. Don't buy anything but a z as other mobos have cut-down i/o.

If it were me, I'd get the 9900k. It is more expensive but when taken over the life of the system it works out to a few quid a year. A good philosophy is to always buy gear that goes to 11.