Some Dell Systems Shipping with 24GB of memory: 8GB DDR4 and 16GB Optane Memory

Subject: Memory, Storage | May 29, 2018 - 04:10 PM |
Tagged: Optane, Intel, g3, dell

Recently I came across an interesting product listing on Dell’s website for its new G3 15” gaming notebook. These are budget-friendly gaming systems with mainstream discrete GeForce graphics cards in them like the GTX 1050 and GTX 1050 Ti. Starting at just $699 they offer a compelling balance of performance and value, though we haven’t yet gotten hands on one for testing.

One tidbit that seemed off to me was this:

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Several of these systems list 24GB of memory through a combination of 8GB of DDR4 and 16GB of Optane Memory for caching. A similar wording exists in the configuration page for these machines:

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Clicking on the More Info link takes you to the “Help Me Choose” portion of the page that details what system memory does, how it helps the performance of your machine, and how Optane comes into the mix. There is important wording to point out that Dell provides (emphasis mine):

Some systems allow you to add Intel® Optane™ memory, which is a system acceleration solution for the 7th Gen and 8th Gen Intel® Core™ processor platforms. This solution comes in a module format and by placing this new memory media between the processor and a slower SATA-based storage devices ( HDD, SSHD or SATA SSD), you are able to store commonly used data and programs closer to the processor, allowing the systems to access this information more quickly and improve overall system performance.

Mixing DRAM with Intel® Optane™ delivers better performance and cost. For example, 4 GB DRAM + 16GB Intel® Optane™ memory delivers better performance and cost than just 8GB DRAM.

What is the difference between Intel® Optane™ memory and DRAM? Does it replace DRAM?
The Intel® Optane™ memory module does not replace DRAM. It can be, however, added to DRAM to increase systems performance.

If I use Intel® Optane™ memory with an HDD to accelerate my games, game launches and level loads become faster and close to that of an SSD experience, but what about the game play? Is the game play impacted?
Game play will not be that different between an SSD and an HDD based systems since the games in loaded into DRAM during play.

While my initial reaction of this as a clever way to trick consumers into thinking they are getting 24GB of memory in their PC when in reality it is only 8GB holds true, there are a lot of interesting angles to take.

First, yes, I believe it is a poor decision to incorporate Optane Memory into the specification of “memory” in these PCs. Optane Memory is an accelerant for system storage, and cannot replace DRAM (as the FAQ on Dell’s website states). If you have 8GB of memory, and your application workload fills that, having 16GB of memory would be a tremendous improvement in performance. Having 16GB of Optane caching on your system will only aid in moving and swapping data from main storage INTO that 8GB pool of physical memory.

Where Dell’s statements hold true though is in instances where memory capacity is not the bottleneck of performance, and your system has a standard spinning hard drive rather than an SSD installed. Optane Memory and its caching capabilities will indeed improve performance more than doubling the main system memory in instances where memory is not the limiter.

I do hope that Dell isn’t choosing to remove SSD options or defaults from these notebooks in order to maintain that performance claim; but based on my quick check, any notebook configuration that has the “24GB of memory” claim to it does NOT offer an SSD upgrade path.

Though it isn't called out one way or the other in the Dell specifications, my expectation is that they are NOT configuring these systems to use the Optane Memory as a part of the Windows page file, which MIGHT show some interesting benefits in regards to lower system memory capacity. Instead, these are likely configured with Optane Memory as a cache for the 1TB hard drive that is also a required piece of the configuration. If I'm incorrect, this config will definitely warrant some more testing and research.

Where the argument might shift is in the idea of performance per dollar improvements to overall system responsiveness. As the cost of DDR4 memory has risen, 16GB of Optane Memory (at around $25) is well below the cost of a single 8GB SO-DIMM for these notebooks (in the $80-90 range), giving OEMs a significant pricing advantage towards their bottom line. And yes, we have proven that Optane Memory works well and accelerates application load times and even level loads in some games.

But will it allow you to run more applications or games that might need or want more than 8GB of system memory? No.

Ideally, these configurations would include both 16GB of DDR4 system memory AND the 16GB of Optane Memory to get the best possible performance. But as system vendors and Intel itself look for ways to differentiate a product stack, while keeping prices lower and margins higher, this is one of the more aggressive tactics we have seen.

I’m curious what Dell’s input on this will be, if this is a direction they plan on continuing or one that they are simply trialing. Will other OEMs follow suit? Hopefully I’ll be able to get some interesting answers this week and during Computex early next month.

For now, it is something that potential buyers of these systems should pay attention to and make sure they are properly informed as to the hardware configuration capabilities and limits.

Source: Dell

May 29, 2018 | 05:21 PM - Posted by HybridDRAMandXPointDIMMsOrNot (not verified)

Is this "Intel® Optane™ memory module" attatched directly to the mamory channels or is is off on some direct to the CPU PCIe lanes on a NVM/M2 slot. Intel is supposed to be producing DIMMs that mix both DRAM and XPoint on the DIMMs and that is attatched to the memory channels and not any PCIe lanes.

May 29, 2018 | 05:25 PM - Posted by quest4glory

It's m.2. They have PCIe NVMe options as well, but chose to place a SATA HDD in there and implement Optane caching instead on these SKUs.

May 29, 2018 | 05:48 PM - Posted by Paul A. Mitchell (not verified)

I'm all for caching, because it already occurs at several
different points in the memory hierarchy,
e.g. L1, L2, L3 caches in CPUs etc.

In addition to those incremental improvements,
I would urge the industry in general to sponsor the R&D
necessary to dedicate an entire DIMM channel, or
pair of dual channels, to a memory resident OS.

A while back, we thought of a way to modify a motherboard
BIOS to support a "Format RAM" option, that would support
a fresh OS install directly into a ramdisk formatted
in an upper-most memory range.

Now, think back to Intel's triple-channel architecture.

While the first 2 banks could be designed in
quad-channel mode, a third bank (one or more DIMM slots)
could be dedicated to Optane DIMMs
(or comparable non-volatile memory of similar performance).

As it turns out, we are almost there by installing four (4)
high-performance M.2 SSDs into a single AIC, and assigning
all 4 to a bootable RAID-0 array (or any other modern
RAID mode dictated by a preferred system design).

See the ASRock Ultra Quad M.2 card and the
ASUS Hyper M.2 x16 card, for 2 available products.

Now, jump ahead to PCIe 4.0, and we then have a PCIe bus
that performs with speeds that exceed the raw bandwidth
of many DDR3 DIMMs. Here's a very crude measurement
I did recently with HDTune on DDR3-1066 DRAM:

Likewise, I believe it's only a matter of time before
ASUS offers a DIMM.2 device that supports a bootable
RAID-0 array of 4 x M.2 NVMe SSDs (instead of only 2).

Just ramp up the transmission clock to 16G on all future
such DIMM.2 devices.

If my crystal ball is working today, I am willing to bet
that ASUS and Intel are already collaborating on the
development of future DIMM.2 devices, so keep your eyes
on the visible horizon, because it's "incoming" very fast

May 29, 2018 | 05:48 PM - Posted by Yuhong Bao (not verified)

"But will it allow you to run more applications or games that might need or want more than 8GB of system memory? "
Well, it is far better than paging to a HDD, and to be honest the average user probably rarely use the kind of applications where such paging would be noticeable.

May 29, 2018 | 06:02 PM - Posted by Paul A. Mitchell (not verified)

> it is far better than paging to a HDD

Your insight reminds me of the "olden" days
when I worked as a systems analyst for a
vendor of super mini-computers that used
virtual memory technology.

There was a very sophisticated "least recently used"
algorithm which would "age" pages and write them
to a spinning HDD, to free up those RAM pages
for use by more active programs.

What happens with Windows 10 if a very large
pagefile.sys is moved to a very large RAID-0 array
consisting of 2x or 4x NVMe SSDs?

Doesn't Windows now use a very similar mapping
between real and virtual memory addresses?

May 31, 2018 | 04:29 PM - Posted by razor512

It does 100% nothing for running more applications at the same time.

Applications do not see the optane modules as RAM, and they are similar to their older SSD caching technologies, but are less conservative in their use since back in the day, an 8GB to 32GB SSD had very limited writes. Optane has far better write endurance and better response times than an SSD, so it focuses more on cashing data that the hard drives struggle with the most, and it will more readily replace that data as needed, as write endurance is less of an issue.

The issue is that optane will not really cache the pagefile, as it changes far too often to benefit from it.

For optane to be considered as RAM, it would need addressing similar to how the GTX 970 did 3.5GB + 512MB. The last 512MB was a fraction of the speed (similar speeds to desktop dual channel DDR3 2133). The drivers treated that last 512MB as a level 2 RAM where compressed data and less frequently access data was stuffed in it.

Optane is not seen this way by the PC, you cannot address it as RAM.

Overall it is false advertising and will be used to mislead less technical customers. When a retail store gets a hold of it, you will see the 24GB in huge font, and the 8 point font for the fine print listing 8 GB of RAM.

It is just like when some stores advertised PCs with 4GB video memory and charged more than prebuilds with faster cards but only 1-2GB of video memory, because the 4GB one was really a card with 512MB or RAM or less, but had turbo cache or some other crap, and they were effectively able to trick some people into spending more money for what was a slower system.

May 31, 2018 | 06:51 PM - Posted by WatchTheHandsWatchTheHandsTheDeckIsStackedWicked (not verified)

Unless it comes with the speed/latency of DRAM and also the endurance then it's just more smoke and mirrors and slight of hand nonsense from Dell.

Remember the Dell laptops with only 2 PCIe 3.0 lanes made available to the TB3 controller chip on those laptops, 40 Gb/s my A$$ from only 2 PCIs 3.0 lanes! And the same goes for all that USB-IF naming confusion related to USB 3.1 and the Type-C plug from factor nonsense that the Laptop OEMs gamed to fool the consumer into expecting 10Gb/s when that USB 3.1 was listed without the Gen 1 or Gen 2 bening included as to lie by omission.

Laptop OEMs can not really be trusted to be truthful when they are gimping things down and trying to overcharge the consumer while no one is paying attention.

May 30, 2018 | 01:48 AM - Posted by James

If it is caching the main hard drive and the page file is on that hard drive, then the Optane memory will end being used as a page file. If you exceed the amounts amount of system memory, then your machine will probably still slow to a crawl. There is still a big difference between even Optane and actual DRAM. Perhaps there is a conspiracy to get people to buy Optane memory by overcharging for DRAM. Maybe it is just a conspiracy to overcharge for DRAM though. It seems like a conspiracy though. I only slept 4 hours last night. Goodnight.

May 30, 2018 | 10:00 AM - Posted by CB

I don't have a problem with Dell saying 24 GB memory. They do clearly show that the 24 is composed of 8 GB of RAM and 16 GB of Optane.

It would be awesome if they used the Optane to cache a large, inexpensive SSD instead of a hard drive. I think the idea of Optane cached, QLC SSD's would be awesome.

June 19, 2018 | 12:59 PM - Posted by Anonymoose (not verified)

Optane =/= RAM.

May 30, 2018 | 12:33 PM - Posted by doesntmeannothing (not verified)

I think it's one of them new low end Optane memories that have a rather low performance in their low capacity forms. Would be nicer just to have bigger SSD alongside the HDD

Plus, the G3 isn't that great really , so the Optane memory shouldn't suffice to make the G3 a good purchase

May 30, 2018 | 04:46 PM - Posted by XPointONDIMMsNowGettingCloser (not verified)

The only question about thes DIMMs(1) is do they require the latest Intel processors. But It does look like DIMM/XPoint SKUs are going to be available soon. So that's XPoint/NVM that's over the Memory Channel and Not PCIe.

"Optane DC Persistent Memory puts 3D Xpoint goodness in DIMM slots"

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