After months of waiting and speculation, AMD has finally taken the lid off its RX Vega series, its clock speeds, capabilities, and pricing. All of these characteristics have been hotly debated of late, with readers asking for (and making predictions about) how it would compare with Nvidia’s year-old Pascal GPUs like the 1070 and 1080.
We now have some preliminary answers to some of those questions, but by no means the entire picture. So here’s how this is going to work: If you want a “regular” GPU, you’ll be able to buy the Vega 56 (56 active CUs) for $ 399. If you want the full Vega 64 chip (the air-cooled variant) you’ll be able to buy that for $ 499. I will admit to being reasonably right in one regard — I predicted that a 1.7GHz base clock for RX Vega made good sense if Vega FE was a 1.6GHz chip. The actual boost clock on the water-cooled version of RX Vega is 1677MHz.
Here’s where things start to get a little wonky. If you want an air-cooled Vega 64 or 56, you’ll be able to buy those straight. If, on the other hand, you want the liquid-cooled Vega 64, you’ll have to buy it as part of a bundle. So, for example, the bundle price on the Vega 64 LC is $ 699 — but for that $ 699, you get a coupon for $ 200 off a Samsung CF791 34-inch WQHD Curved FreeSync monitor, a $ 100 discount on a Ryzen 7 CPU + motherboard bundle, and two free games (Wolfenstein II and Prey in North America).
I’m not sure this bundle idea is the best way to move product. Don’t get me wrong; $ 300 in coupons for quality hardware is a worthwhile bonus, as are the two solid games — but only if you were already planning to build a new system in the first place. That Ryzen 7 CPU + motherboard bundle is still going to cost you over $ 200, and even the sale price on the CF791 is $ 749. If you’re planning to drop serious cash on a new rig, these offers are helpful. Otherwise, not so much. In fact, I think AMD knows it, and has deliberately made the liquid-cooled Vega a bundle-only part precisely because it knows it either can’t sell enough cards at that price to make any money or because they’re only planning a very limited run in the first place.
What About Performance?
Performance is… not what people were hoping for. AMD didn’t reveal a lot of details, but they mainly focused on emphasizing minimum frame rates and overall frame rate smoothness. Both of these are good qualities for a chip, but people expected RX Vega to be some kind of super GTX 1080 Ti killer. And… well, it isn’t. AMD has stated that they expect the RX Vega to trade blows with the GTX 1080, and the overall pricing reflects that expectation. So here’s how this breaks down:
RX Vega 56: 1156MHz base clock, 1471MHz boost, 64 ROPs, 224 texture units, 3584 shader cores, 2048-bit memory bus, 410GB/s memory bandwidth, 8GB of HBM2, and a 210W TDP.
RX Vega 64 (Air): 1247MHz base clock, 1546MHz Boost, 64 ROPS, 256 texture units, 4096 shader cores, 2048-bit memory bus, 484GB/s of memory bandwidth, and a TDP of 295W.
RX Vega 64 (Water): 1406MHz base clock, 1677MHz boost clock, 64 ROPs, 256 texture units, 4096 shader cores, 2048-bit memory bus, 484GB/s of memory bandwidth, and a 345W TDP.
From this point forward, air-cooled and water-cooled will be referred to as AC and WC for the sake of my sanity.
As always, we’ll hold on final judgment until we have shipping, tested silicon, but these are not the kind of figures people were hoping for. The GTX 1080 Ti has a TDP of 250W. Anyone who says “TDP doesn’t equal power consumption” is absolutely, 100 percent right, but TDP ratings tend to at least point in the general direction of power consumption, and a rating of 295W for the AC Vega and 345W for the WC version tells us a lot about how these chips handle clock rates.
Consider: The RX Vega 64 AC is clocked 8 percent higher (base) and 5 percent higher (boost) than the RX Vega 56, and has 15 percent more cores. Yet the TDP difference between the two chips is enormous, with Vega 64 AC drawing 1.4x more power than Vega 56. Now, as we’ve often discussed before, power consumption in GPUs isn’t linear — it grows at the square or cube of the voltage increase, and clock speed or memory clock increases will only make that worse.
Being able to compare with RX Vega 64 LC makes the problem a bit easier to see. The AC and LC variants of Vega only differ in clock speeds. RX Vega LC’s base clock is 1.13x higher than Vega AC, with a boost clock gain of 1.08x. But those gains come at the cost of an additional 1.17x TDP. In other words, at these frequencies, Vega’s power consumption curve is now rising faster than its clock speeds are.
We’re not preemptively calling this Nvidia’s game, not by a long shot. But AMD’s pricing, bundle, and overall part positioning seem to imply the RX Vega 56 will compete against the GTX 1070 while the Vega 64 competes against the GTX 1080. And if you care about power consumption, unless AMD has some crazy last minute optimizations up their sleeve, we’ll be watching the company’s new GPU face off with Nvidia’s May 2016 flagship, not the more recently launched GTX 1080 Ti.