Personal speculation on AMD Navi

Hey guys, A lot of folks (read: "Nvidia fanboys") are disappointed with the release of the AMD Radeon VII. Even though this release was teased back in April of 2018. While I do understand some of the disappointment (it's not the RTX killer we had hoped for), I do think it actually gives us a clue on what we can expect from AMD Navi. A lot of people see the AMD Radeon VII as a sign that AMD Navi won't be anything good, while I personally think this is far from the truth. So In this post, I'll be showing you why I still have my hopes up. I'm not an AMD fanboy what-so-ever but I think people should give AMD credit for what they are doing. Without any further ado, let's dive into it!

AMD Ryzen

So it's no secret that AMD Ryzen (I name Threadripper and Epyc under Ryzen for simplicity sake) shook up the CPU market heavily and I can't blame them for doing so. AMD Ryzen is a beast as it keeps up very well with Intel on the single-core performance (only lacking behind slightly in most cases) while beating it to a crisp in multi-core performance while also being at a fair price. Good job AMD! Now, what does this have to do with Navi you ask? Well, simply put, quite a bit. First of all, it shows that AMD is still capable of developing capable chips, even when lacking a major R&D budget that Intel and Nvidia do have. AMD Ryzen gave AMD a much-needed boost in profit, allowing them to spend more on R&D, not only for the CPU market but also the GPU and APU market. This means that, given the increase in R&D budget, AMD Navi should be able to develop better. Not just that, but it shows that AMD is willing to go to massive efforts to get themselves back in the race.

HBM2 and GDDR6

AMD Vega showed us that AMD is heavily fiddling with HBM2 on their higher-end chips (namely the RX Vega 56 and RX Vega 64), this is confirmed with the release of the AMD Radeon VII. But add to this the fact that leaks (which, at the time of writing this remain unconfirmed) indicated that the lower-end Navi cards are gonna use GDDR6 can be a bit confusing. As you guys know, HBM2 is placed on the same substrate as the GPU itself as to keep the bandwidth high and the latencies low (PCMR reference anyone?). We also know that most of the time, the lower-end chips are more often than not just chips that didn't pass the required tests to become a higher-end chip. But we also know that HBM2 is pretty darn expensive (according to some sources, it costs AMD $30 per chip to produce - containing ~4GB per chip). GDDR6, on the other hand, is also quite expensive but since AMD said Navi will be using "Next-Gen memory", one could argue that this might be GDDR6 anyways. As such, I don't think we'll see HBM2 on the lower-end spectrum of Navi cards just yet. However, I have little to no doubt that the higher-end of the Navi cards will be using HBM2, especially considering the AMD Radeon VII and the next point (the AMD Infinity Fabric) I'll talk about. However, maybe AMD is gonna bin the HBM2 for use in the lower-end cards as well? who knows; you don't need 16GB of VRAM for games anyways.

AMD Infinity Fabric

We all know that AMD is using this thing called "Infinity Fabric", which is basically just AMD saying: "Why don't we just add more dies". While the Infinity Fabric comes with a minor performance penalty (though, this is as far as I'm aware pretty insignificant) it does sound pretty dope. We also know that AMD wants to take it to the next level by having APUs have their iGPU connected to the CPU over this Infinity Fabric (I'm currently not aware whether they have already done this). As such, it should come as no surprise that AMD might take the same approach as they did with Epyc and Threadripper with their Navi GPU. It would also be interesting to see whether AMD will be doing something like NVLink with their Infinity Fabric. Tho looking at some pictures I can find, it looks like this might actually happen. On their website we can see two interesting cards: The AMD Radeon Instinct MI60 and it's little brother, MI50. These cards both have extra fingers where we also saw Crossfire, SLI and NVLink connectors. On their website, they also state that these cards support the "AMD Infinity Fabric Link technology". Taking a look at the older MI25 that lacks these fingers, I can also find no sign that these cards support the Infinity Fabric. This could be a clear indication that these fingers are the fingers for the Infinity Fabric. Basically, to me, there is little to no doubt AMD will do something with their Infinity Fabric on the Navi cards.

Enterprise to Consumer

As we all know, the enterprise tends to be pretty far in front of consumers when it comes to tech. Nvidia Pascal and AMD Vega (especially the 7nm variant) are great examples of this. Before we got the GTX1000-series (which use the Pascal architecture), we had already seen the Nvidia P4, P40 and P100 cards in the enterprise segment. And before we had the Radeon VII (which uses Vega 7nm), we already had the AMD Instinct MI60 and M50. This should come as no surprise but often the chips that are rejected to become the enterprise chips, are binned to become prosumer or consumer chips instead.

Final words

Currently, I have seen no AMD Navi based cards in the enterprise segment just yet so I, unfortunately, cannot deduce (yet) whether any of the speculations I just did are true. As time goes on, I'll add stuff to this post to reflect the updates I found on the subject so please do keep coming back every now and then to see whether anything has changed. I'm very curious to see whether any of my speculations will become true for the AMD Navi cards and I hope you are to. That was it for now and I will see you in the next one! [g33kout]

Update 10/02/2019

One of my readers has pointed me to the fact that Samsung made an announcement a while ago that they started developing a lower-cost HBM by removing a buffer die and decreasing the number of TSVs (Through-Silicon Via). This HBM does have a lower bandwidth (200GB/s instead of 300GB/s+) but I think that loss of bandwidth won't be such a major deal as opposed to the possible price reduction. I'm still not sure that it's gonna happen but knowing how fast technology can go nowadays, there is a chance it actually might end up in AMD Navi.


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