AMD Ryzen 5 1500X review: after the six-core highs come the quad-core lows

AMD Ryzen 5 1500X review

The Ryzen 5 1500X is the scaled down mid-range partner to AMD’s finest gaming chip ever, the R5 1600X. It’s retailing for $189 (£190) which then puts the first Intel K-series i3, the 7350K, firmly in its sights.

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It’s almost an unfair comparison because we’re talking about pitching the quad-core, eight-thread 1500X against a HyperThreaded dual-core chip with half the thread-count of this Ryzen 5 processor, but that’s just the way things are with the Intel vs. AMD debate in 2017.

The big questions for this cut-down Ryzen 5 chip though are: how well does the architecture deal with being chopped up this much, can it still keep pace with Intel’s gaming prowess and can it justify its price in the face of its hexcore siblings?

Point your cursor at whichever of the jump links takes your fancy and you’ll get there in no time. 

AMD Ryzen 5 1500X specs

AMD Ryzen 5 1500X specs

The R5 1500X is the top-end quad-core Ryzen CPU, but because of the addition of simultaneous multi-threading (SMT) in the mix the chip comes with a full eight threads of processing potential. That’s the same essential make-up of the Core i7 7700K from Intel, though without the gaming grunt of their flagship Kaby Lake processor.

In a financially-smart move AMD are using the same base processor design to create all the Ryzen 5 and Ryzen 7 chips. They’ve created a single eight-core, sixteen thread design - the top-end Ryzen 7 1800X - and for the lower-spec parts are simple disabling cores and/or clocking them slower. Under the heatspreader then this quad-core 1500X is actually just a hobbled octa-core CPU.

That makes things easier, and cheaper, from an R&D perspective as well as from a manufacturing one. The 14nm production process is still relatively new, especially for AMD CPUs, and so this method allows them to still use any silicon that comes off the production line which cannot manage to get all its cores and threads running at the speeds needed for the top chips. These less-capable processors can then be repurposed and shipped as slower Ryzen 7 chips or cut down Ryzen 5 CPUs.

For the uninitiated, the Zen processor design is built from quad-core blocks of silicon called core complexes (CCX). For the Ryzen chips they incorporate a pair of these CCX to make up the full eight-core base design, which then communicate with one another across a proprietary interconnect AMD calls Infinity Fabric.

Like with the cut-down hexcore design AMD are making sure to keep things symmetrical when they make their incisions into the silicon. They’re arranging the quad-core variants in such a way as to enable half the four core CCX on either side of the connecting Infinity Fabric in a two-plus-two layout.

This is to ensure Windows scheduler doesn’t get too out of whack when trying to portion workloads for the different threads and should ensure they’re not oddly metered out across the Infinity Fabric interconnect if they can be kept to a single physical core. 

The 1500X is also the first 65W ‘X’ series chip. That means as well as having a lower TDP it also doesn’t struggle under the weird 20॰C offset that the 95W ‘X’ chips sport.

If you want a more detailed run-down of the Zen architecture we’ve gone into greater depth in our main AMD Zen feature.

AMD Ryzen 5 1500X benchmarks

AMD Ryzen 5 1500X benchmarks

AMD Ryzen 5 1500X overclocking

 

AMD Ryzen 5 1500X performance

AMD Ryzen 5 1500X performance

Even if we’re looking at the R5 1500X purely in the context of how it performs up against the Core i3 7350K it ends up looking a little muddled, more so if you bring the Ryzen 5 1600X or straight 1600 into the equation. The hexcore chips are so good at what they do because of the combination of relatively high clockspeed and hefty multi-threaded grunt, all offsetting their less-powerful straight line gaming performance.

The slower-paced quad-core, eight-thread chip on the other hand doesn’t have that much extra in the tank. That means it drops well behind the higher spec Ryzen 5 CPUs in all tests, and sometimes even behind the dual-core Intel processor when it comes to gaming. And, considering how close it is in terms of pricing, the six-core, 1600 is a far more tempting alternative. For the sake of $30 I think you’d be a fool to opt for the quad instead.

AMD Ryzen 5 vs Intel Core i5

That’s true whether you’re looking at the gaming frame rates or the straight CPU performance in the rendering or encoding tests. The extra threads of the 1500X over the 7350K means it’s got the win over the dual-core chip, but compared with the hexcore 1600X (and, by extension, the R5 1600 too) it’s a long way off.

It’s actually only got a relatively small multi-threaded lead over the resolutely quad-core i5 6600K too. That may be primarily down to the fact the 6600K is clocked so high to begin with, but the 1500X couldn’t even break the 4GHz barrier when overclocked, so that delta is even more crushed when you push the 6600K up to full speed at 4.6GHz.

What the 1500X can offer though is impressively low temperatures, however, it’s not like the Ryzen 5 1600X is particularly toasty once you discount the odd 20॰C temperature offset they’ve stuck on the 95W chips.

AMD Ryzen 5 1500X verdict

AMD Ryzen 5 1500X verdict

After the highs of the Ryzen 5 1600X its quad-core sibling feels like a bit of a disappointment. I’m still trying to figure out what it’s really for. At just under $200 it’s simply priced too close to the $219 (£220) hexcore 1600. That’s a six-core, 12-thread CPU which is essentially just a down-clocked version of the 1600X. It’s still multiplier-unlocked which ought to mean overclocking that chip a little should net you practically the same performance as the ‘X’ series CPU.

So, what are you getting by saving $30 and losing two physical cores and all the extra gaming performance the hexcore processors can offer? Nada. It’s marginally cooler than the 1600X under load, but not by enough to make any genuine difference if you’re running a decent air or closed-loop liquid cooler. And it certainly doesn’t allow the 1500X to overclock any better, in fact we couldn’t even get it up to 4GHz.

The Ryzen 5 1500X’s gaming chops also leave a little to be desired, sometimes even losing out to the dual-core 7350K, though only in a few tests. But generally it’s relatively far behind the six-core Ryzen on all counts. There’s also the fact that even though it’s got twice the thread-count of the quad-core Intel 6600K it’s nowhere near being twice as quick in the multi-threaded tests where you’d expect a decent lead.

Maybe at $150 the R5 1500X might make some sense, but I’ve got a feeling that’s where pricing is likely to start for the Ryzen 3 processors which are set to follow in probably only a matter of weeks. Those will be the budget chips, however it still remains to be seen how well those super cut-down Ryzens are going to be able to match up to the lower-end of Intel's gaming processors.

At this price though I’m really struggling to find a reason to recommend the Ryzen 5 1500X so, well, I’m not going to. Save up a little and get a 1600 instead, I mean it's just $15 per extra core...

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Shriven avatarShadowized avatarDave James avatarAnakhoresis avatar
Anakhoresis Avatar
606
7 Months ago

I don't see why this is so disappointing. Sure, the 1600 is only $30 more, but where it's at it does perfectly fine. It competes pretty dang well with the i5-6600k, which is also $30 more, and while the dual-core i3 may offer higher clock speeds and therefore sometimes better gaming, just like the i7-7700k/1800x, as a general computing CPU the 1500x is the better deal. Is it exciting? No, but is it still a pretty solid offering when someone's trying to penny pinch? Yes. It feels like in most areas you can fall into the 'trap' of "Just a little bit (like $30?) more" with components, so it doesn't seem bad to have an offering to fill the space.

2
Dave James Avatar
459
7 Months ago

I do see your point re. always being able to spend just a little more on components, but I genuinely think the performance/spec gap between the 1500X and 1600 is way bigger than the $30 saving. Normally that small a price differential wouldn't deliver something so much better specced.

3
Shriven Avatar
3456
7 Months ago

Bumf. Gut punch.

1
Shadowized Avatar
140
7 Months ago

any reason you're using 2666mhz memory again when you used 3000mhz in the 1600X review? seems odd since its on the same board with the same ram, or is it just an error with copy/pasting the template from a previous post?

agreed though with the closing thoughts that the r5 1600's are definitely the way to go, absolute no-brainer purchase for such a small price increase, hell, Intel charges 100$ more for just hyperthreading.

1
Dave James Avatar
459
7 Months ago

Sadly, once again the vagaries of Ryzen memory support came into play with the 1500X. The same board, same BIOS, same DIMMs, and yet with the 1500X it couldn't manage to hit 3,000MHz. You're right though, I should have made the point in the article, but it slipped my mind as I was putting it together.

1