Motherboard Mini-DTX petition thread!

[Runamok81]

I think the research recently has proven otherwise. At work, but this article summarizes findings on ram speeds yielding performance boosts: http://www.digitaltrends.com/computing/highspeed-ddr4-shown-to-improve-in-game-performance/ - they quote this article.

Looks like I underestimated the performance gap between the bottom (2133MHz) and top (4000MHz) frequencies of RAM. Looks like the diff between is closer to 10-20% depending on application! Encoding video. Big difference. In gaming.. FPS the gap isn't as huge. But still larger than I thought.

SO-DIMM is currently capped at 3000MHz. Example here. So, I think it's fair to say the Mobo Manufacturers that go SO-DIMM are leaving say... 5% gaming performance on the table? More for other applications.

 

[robbee]

Looks like I underestimated the performance gap between the bottom (2133MHz) and top (4000MHz) frequencies of RAM. Looks like the diff between is closer to 10-20% depending on application! Encoding video. Big difference. In gaming.. FPS the gap isn't as huge. But still larger than I thought.

SO-DIMM is currently capped at 3000MHz. Example here. So, I think it's fair to say the Mobo Manufacturers that go SO-DIMM are leaving say... 5% gaming performance on the table? More for other applications.

Improving max fps without improving minimum fps won't really improve the perceived performance though. Frametimes should be benchmarked for a realistic image.

 

[Phuncz]

Especially because DDR4-4000 is about 2,5 times the price of DDR4-2400, so extreme diminishing returns.

 

[iFreilicht]

This please. I just don't see the need for full size DIMM anymore.

I do understand that higher quality RAM (better timings, ECC) is only offered in full size. But I think those benefits are overated? We're no longer in an age where RAM timings can net you a significant performance advantage. In all of the latest "RAM performance" articles I've read there is maybe ... 2% ? of performance to eek out between the bottom-barrel RAM and top.

SO-DIMM makes me happy.

One extremely good reason: Low profile RAM sticks. There are quite a few people that use large CPU coolers which require LP DIMMs. They offer additional flexibility.

 

[BirdofPrey]

As per usual, the benefit you gain from upgrading various components depends on your use case, but too many people are obsessed with getting the best there is for a gaming PC even if having the fastest processor and gobs of super fast memory only net a few FPS in gaming (In fact, at this point, there isn't even much reason to get the latest and greatest GPU if you still have a 1080p monitor).

Still, I agree that it would be nice to see some motherboards with SO-DIMM slots. Not only does it let you use more memory if you actually need to (or just more smaller-capacity RAM sticks to save money), it also opens up quad channel memory which could be good for marketing. It also might leave more room for the other features that sell well like more M.2 and ports (though I am still waiting to see them replace the 6-8 SATA/SATA-Express ports with a pair of U.2 ports and a SATA breakout cable for additional freed up space).

With small systems, every bit of saved space is critical, but most companies aren't doing much to save space on their mITX boards.

 

[zovc]

I just wanted to jump in and say that, even though it's obvious, mini-DTX is bigger than mini-ITX.

I have a M350 enclosure from mini-box that I planned to put my HTPC inside of. That case is TINY, I have this ECS B85H3-M9 from an old build which you can see is still listed as Mini-ITX. It's actually mini-DTX, note the PCI slot above the PCI-E slot... that ECS board doesn't fit in the M350. Whoops!

Not really a fault of any one party, I suppose, and definitely not a real fault of mini-DTX but it could complicate or confuse things depending on how well and clearly the two standards are designated.

 

[jeshikat]

That's a good point, but the vast majority of ITX cases sold are 2-slot so that shouldn't be too much of a problem.

 

[zovc]

That's a good point, but the vast majority of ITX cases sold are 2-slot so that shouldn't be too much of a problem.

That is true. Aren't most more modern mITX cases designed to be used with a riser card? I suppose it wouldn't be too hard to double them up, but some of them are laid out fairly snug. Would you be able to fit a mDTX board in something like the Fractal Design Node 202? What about something like the S4 Mini or the Sentry? These all have two slots, but so far as I know they're not really designed to accommodate two PCI (e) devices.

I definitely appreciate the added versatility (and many of the random awesome things you can install in expansion slots), but I also really like the push for the smallest volume possible in a lot of the current case designs that are emerging. When considering switching to mITX, I had to decide if I'd really miss hot swap bays and cup holders and whatnot in my 5.25" drive bays.

 

[jeshikat]

That is true. Aren't most more modern mITX cases designed to be used with a riser card?

All the slim console-style cases use risers and many of the indie cases in development use flexible extenders.

Would you be able to fit a mDTX board in something like the Fractal Design Node 202? What about something like the S4 Mini or the Sentry?

202 and Sentry maybe not, the M1 though was designed with Mini-DTX in mind, it's part of why it has 3 slots.

definitely appreciate the added versatility (and many of the random awesome things you can install in expansion slots), but I also really like the push for the smallest volume possible in a lot of the current case designs that are emerging.

And Mini-DTX is part of that, it's more of a way to downsize microATX than trying to force ITX to go bigger.

 

[zovc]

That's a good way of looking at it. The only reason I could think for the M1 having the 3 slots was to house even the tallest of GPUs.

 

[BirdofPrey]

You might be able to jam a mDTX into a Node 202. The positioning of the cards looks right and the riser is a right angle with an extension plugged in. I'm not sure if the middle frame piece would need to be cut for the motherboard to fit, but you would need to modify it to use a 2 slot riser.

Zaber Sentry on the other hand looks to have 0 slack space for any such modifications.

 

[iFreilicht]

That's a good way of looking at it. The only reason I could think for the M1 having the 3 slots was to house even the tallest of GPUs.

@Necere can correct me if I'm wrong, but the M1 needed space in the bottom for fans/radiators, that's why it's taller than two slots. And at that point it was so tall that a third slot and thus mDTX support came for free. That also had the benefit of allowing cards like the Titan Z to fit, which had a 2.5 slot cooler design. It was a case of an awful lot of functionality being added with very little cost.

 

[Necere]

@Necere can correct me if I'm wrong, but the M1 needed space in the bottom for fans/radiators, that's why it's taller than two slots. And at that point it was so tall that a third slot and thus mDTX support came for free. That also had the benefit of allowing cards like the Titan Z to fit, which had a 2.5 slot cooler design. It was a case of an awful lot of functionality being added with very little cost.

It didn't need the space, per se, but it offered too much utility not to do. You get:

• Space for intake fans
• Additional drive mounting
• A third expansion slot, which is useful for some 2- and 3-slot MDTX/small mATX motherboards, or for fan controllers, or even for moving the GPU down via a flex riser
• Space for a bottom slim rad (not something I intentionally designed it for, but how a lot of people have nevertheless used it)
• Space for a standalone pump
• Cable space
• Front I/O is below the GPU, allowing for longer cards and easier installation

All that for just 20mm of height, which is really not much in the scheme of things, and has enabled so many great and creative builds. Of course there've been people that complained that this made it bigger than it strictly needs to be, and the ever present "just add one more slot and it would be mATX!", but there will always be critics. I think in the end I made the right choice, and it wouldn't be all that it is had I done otherwise.

 

[Phuncz]

I think in the end I made the right choice, and it wouldn't be all that it is had I done otherwise.

I'm very happy you did, it allowed my 290X to perform beyond what I thought was possible, noise and temperature-wise.

 

[dtallon13]

Here's a quick mockup of a M-DTX board I did(Just cut up an existing ATX one) With the new Ryzen CPUs, we have 28 lanes to work with, which is enough for an x16 dual GPU card (Upcoming Vega GPUs will use HBM which means they can be on much shorter PCBs, possibly allowing for a dual chip ITX card), an x8 NIC (10GBe anyone?), and running the M.2 slot at x4. You'll notice there's no headers to the left of the PCIe slots, but I found places for the few headers that I think most people will use. IIRC, my Haswell ITX board has not one but two COM headers. Seriously? I know some people still need real COM headers and can't use USB adapters, but I think that's more niche than DTX. Removing those allows for only an extra 18mm added width. Anyway, sorry for the wall of text, here's the image.

 

[|||]

Ryzen only has 24 lanes, 4 for the chipset, 4 for an M.2 and can be split off for SATA. There will be only 16 lanes available for GPUs; it can be split to x8/x8 using X370 chipsets.

The CPU pins for memory, PCIe, and Power are on one side of the CPU or another, which is why you see all motherboards oriented in basically the same way, to limit the number of PCB layers needed to handle all of the traces. Your design could potentially be possible if you rotated the socket, chipset, and memory 90 degrees counter-clockwise, but I'd be concerned with the memory traces, as memory speed has been shown to currently be the AM4's Achilles heel. Also, you'd need SATA ports, as it would eliminate the market for a board with only a single M.2 slot...you could handle a couple in a right-angle connector at the lower left-hand corner and a couple more in vertically oriented connectors somewhere around the chipset. The power circuitry take up more room than you have given it, and there are keep-out zones for the CPU cooler, as well.

 

[dtallon13]

Ryzen only has 24 lanes, 4 for the chipset, 4 for an M.2 and can be split off for SATA. There will be only 16 lanes available for GPUs; it can be split to x8/x8 using X370 chipsets.

The CPU pins for memory, PCIe, and Power are on one side of the CPU or another, which is why you see all motherboards oriented in basically the same way, to limit the number of PCB layers needed to handle all of the traces. Your design could potentially be possible if you rotated the socket, chipset, and memory 90 degrees counter-clockwise, but I'd be concerned with the memory traces, as memory speed has been shown to currently be the AM4's Achilles heel. Also, you'd need SATA ports, as it would eliminate the market for a board with only a single M.2 slot...you could handle a couple in a right-angle connector at the lower left-hand corner and a couple more in vertically oriented connectors somewhere around the chipset. The power circuitry take up more room than you have given it, and there are keep-out zones for the CPU cooler, as well.

Thanks for your input! Like I said, it's just a quick mockup as I know only basic circuitry design. I gave it the same amount of CPU clearance that was on the ATX board I modified, and I did think it seemed small. But I do think it may be possible in the near future if manufacturers notice us. And as far as the CPU power circuitry goes, I think I recall seeing a board with a little daughterboard for that, but that may not have been an actual unit.

 

[Phryq]

give it 4 ram slots and 2 m.2 slots!!!

Then I can be in heaven

 

[owliwar]

ohh! so thats what they are called
I just build my brother a pc with the asrock mobo

sweet sweet spot of money x size here in my country, It was like, the cheapest 1151 motherboard.

 

[jeshikat]

give it 4 ram slots

That's unlikely (other than using SODIMM like the EPC612D4I) though since Mini-DTX is still Mini-ITX in width.

It was like, the cheapest 1151 motherboard.

Yeah, there are some pseudo Mini-DTX boards out there. They're designed as cheap microATX boards (since the PCB is smaller they're cheaper to manufacturer) rather than a step above Mini-ITX boards though.