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Deep dive into flash storage vs. hard drive storage

If your company is looking for high-performance storage, you may be looking at flash. But knowing you want flash storage isn't enough in the current market. Flash storage comes in many forms, and the flash storage landscape is constantly changing. Dennis Martin, founder and president of Demartek, a computer industry analyst firm, spoke with Senior News Director Dave Raffo about different types of flash implementation and the future of flash storage. For Martin, one thing is clear: When it comes to flash storage vs. hard drive storage, flash almost always comes out on top.

Martin said that he's tested all-flash arrays under a variety of workloads, and they work well under most of them. What's more, all-flash arrays can often handle multiple workloads at once.

When considering an upgrade to all-flash, you have an option to upgrade an existing controller or get one that was built from the ground up to work with flash. According to Martin, it's always preferable to have a controller built from the ground up, because it will be built to work with the speeds of flash. If you have a new system built with flash storage vs. hard drive storage retrofitted to include flash, the new system will simply be more efficient.

Martin had a similar opinion about hybrid arrays. Although hybrid arrays are a step up from hard drives, they're simply not as good as all-flash arrays. Martin said that, in flash storage vs. hard drive storage, flash is much more efficient.

According to Martin, it's only a matter of time before everyone jumps on the flash bandwagon. For now, companies can get by without it. But Martin told Raffo that once you try flash, "You're going to wonder why you didn't do it before." If companies try flash storage vs. hard drive storage, Martin argued that they'll find a noticeable difference in favor of flash.

Martin also discussed why he believes NAND flash is coming to the end of its lifecycle. He noted that several companies, including Hewlett Packard Enterprise (HPE) and a joint venture between Intel and Micron, are designing new types of storage that are expected to be more efficient than current NAND flash technology. However, he said it still has a while to go before it'll be phased out completely. "We've got some people that say five years left for NAND, maybe longer, hard to say, but there are other ones coming," Martin said.

In terms of server-side flash, Martin said it has benefits and drawbacks.  Putting flash in the server means you have extremely small latency, but you need to have the capacity you need in the server. Using external storage will create a bit more latency, but it offers a lot more capacity.

Editor's note:

This is the first part of a two-part interview about flash storage. The second part breaks down the different types of flash storage available on the market.

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Transcript - Deep dive into flash storage vs. hard drive storage

Hello, my name is Dave Raffo, I'm the senior news director for TechTarget's Storage Media sites. Joining me today to discuss solid-state deployment options is Dennis Martin, founder and president of Demartek, an industry analyst firm with its own hands-on testing lab. Welcome Dennis.

Dennis Martin: Thanks, Dave.

What use cases are best served with all-flash arrays?

Martin: We've tested all-flash arrays under lots of different use cases, and just about all of them actually worked really well with flash. One of the things we've been doing is not just putting one or two workloads on there, but multiple workloads, and we're finding that they actually work pretty well.

We hear about flash arrays built from the ground up and legacy systems that use controllers built for hard disk drives and put flash drives behind them. [What are] the advantages or disadvantages of using a system designed specifically for flash?

Martin: So a lot of the legacy controllers were built, of course, for hard drives, and so that means that the architecture is built around the speed of the hard drive or the hard drives. And the newer systems that are built from the ground up with all-flash are just built assuming you've got something much faster than hard drives. So I see the problem would be, taking an older system, you kind of have to retrofit it, and you have to go back and fix things from an architectural stand point, and sometimes you can't. So if you start from ground zero with something completely new, then you can design for flash or whatever comes after flash, with those kinds of speeds in mind.

Do most organizations really need an all-flash array?

Martin: Let me take it back to like, different industries. So, when cars were first introduced, most people didn't need cars, but once the prices got to be reasonable it's like, how could you not get a car, right? So I kind of view flash as the same thing. You can get by without flash, but I would say once you try flash, either in a laptop drive or enterprise storage system, you're going to wonder why you didn't do it before.

If you have an application that can run entirely in flash on a hybrid array, would that performance be just as good as using an all-flash array?

Martin: Hybrid systems do pretty well. They do a nice job of improving the performance. We've seen, though, when you go to all-flash, you just get better performance. Now, I guess the jump would be if I'm at hard drive only, and then I'm in a hybrid, and then I'm in a flash, the hybrid is going to give you a nice big bump, but all-flash will give you even more.

Are we coming to the end of NAND flash, and, if so, how long does it have, and what technology or technologies will replace it?

Martin: The industry has been talking about getting to the end of NAND flash for a while, but we're not quite there yet. So there's still more work that they can do, they know that they can do. Lately, the shift to 3D opens up a whole new set of things that can be done with flash. However, there are other technologies that are coming out; of course, they've been on the drawing board for quite a while as well.

Obviously, Intel and Micron made an announcement in the summer about this new 3D XPoint, [HPE] is talking about other kinds of things. So Memristor and phase change, all these other ones are sort of lurking in the background just kind of waiting to get developed, and make sure they get to the right capacities and price points and everything. So we've got some people that say five years left for NAND, maybe longer, hard to say, but there are other ones coming.

What are the advantages and disadvantages in using server-side flash?

Martin: So when you put it in the server, obviously, putting the flash in the server is much closer to the processor where the work's being done, so if you can get the amount of capacity that you need in the server, that's a great way to go because your latency is going to be extremely small. Whereas, if you go out to an external storage system, then your capacity opportunities are much bigger. Latency is going to be a little bit more because now you're going over a wire of some kind to get to the storage system.

So I like server-side flash. If you can get the capacity you need in the server, I'd say go for it. It's a great supplement to those things. If you don't have quite enough memory to put the whole thing in memory, if you got the local flash there, that's a great way to go.

Thanks Dennis.

Martin: Thanks Dave.

That wraps up today's session on solid-state deployment options with Dennis Martin. I hope you found this informative, thanks for watching.

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