Question PCIe & laptop motherbaords?

[Armani316]

He guys,

Can someone please clarify the following for me:

1. From my basic understanding, laptop motherboards do not use PCIe connectors, so the entire discussion about PCIe 4.0 & 5.0 is irrelevant for laptops. Is this correct?
What confused me is what when I look at the tech specs of M.2 NVMe SSDs (e.g. SSD 970 EVO Plus NVMe) it mentions the PCIe & NVMe versions supported; the PCIe part totally threw me off.

2. Also, with respect to laptops, I was reading an article the other day on Techgage (https://techgage.com/news/what-can-we-expect-from-pcie-4-0-and-5-0-bandwidth/). It states the following:

"Another scenario that will likely catch on, even with consumer gear, is I/O aggregation, meaning fitting more USB, SATA, M.2, U.2 ports onto fewer lanes. In the case of USB 3.1, and even Thunderbolt to some extent, motherboard manufacturers could push more of those ports into fewer lanes, allowing for more ports to be made available, without encroaching on PCIe lanes dedicated to graphics or M.2 storage."

Is this applicable only for desktops or also for laptops?

3. If it is applicable for laptops, can we expect more ports in 17" laptops (e.g. https://www.razer.com/gaming-laptops/razer-blade-pro) in a couple of years time once the H-series of Intel's 10nm CPUs hit the market? Will it be possible to have a total of 6-8 USB ports with like 3-4 USB Type A ports (3.2 Gen 2 at 10 Gbps) AND 3-4 USB Type C Ports (Both USB4 + Thunderbolt 3 at 40 Gbps)?

I mentioned 17" laptops specifically since they actually have the physical space to house more ports, so I'm not sure what's currently stopping them from adding more ports.

I'd really appreciate it if someone could clarify the above points for me. Thank you!

 

[Eximo]

1) Not the actual PCIe physical slot no, but the bus in the computer is still PCIe (Serial) The chip and chipset provide PCIe communications bandwidth. This is doled out for almost everything. Graphics, USB, Network, Sound all consume PCIe lanes internally on the motherboard. Newer generations of PCIe offer more bandwidth, so even a 4x device can now use a 1x lane, you have that much more to use if you keep the lane count the same. (PCIe 5 should be four times as fast as PCIe 3 the typical standard of today)

2) Typically the chipsets have been getting more lanes. Intel CPUs have stagnated a little in terms of increases, most people can get away with 16x or 8x for graphics, and 4x for a single fast drive. Everything else would go to the chipset which has roughly 4x lanes of bandwidth to share with everything else. The chipset might offer 20x or more lanes. The idea there is you aren't using everything simultaneously and their needs aren't as great as the bandwidth available. Obviously at some point after plugging in many high bandwidth devices things will slow down. Faster PCIe generations might actually let the chipsets be designed with fewer lanes as well. It will save them money to not have to build the switching, so the article is right if they keep the lane count the same, but wrong if they choose to consolidate more.

3) Probably not much more than now. It isn't necessary. If you need to plug that many things in you should be using a powered external USB hub. If they all need that bandwidth simultaneously, you wouldn't be wanting to use a laptop or a USB hub. Something like a powerful workstation with a dedicated expansion card would make more sense. Assuming the data doesn't need to go to the computer anyway.

I suppose at that point some new PCIe 5 based external port, such as thunderbolt, could make an external device have nearly limitless ports being used at once, at least compared to today. But everything will grow with it. Graphics cards and storage that use that bandwidth will soon follow.

 

[Armani316]

@Eximo Thank you so very much for your thorough response. I really appreciate it. This has definitely cleared up my confusion about this topic. I'm planning on upgrading my laptop but I'm in no rush at all - my current laptop can easily give me a couple more years. I typically go for a super high-end laptop & keep it for many years, so aspects like future-proofing & upgradability are very important for me. I'm in the process of deciding on the specs / protocols that I want my next laptop to have. I'm specifically in the market for a 15" or 17" thin & light gaming laptop (Razer Blade 15, Razer Blade Pro 17, Gigabyte AERO 15, Alienware m15 or m17, etc.) but I'm not going for this year's or even next year's models.

Looks like H1 2021 is the best time to go for one. I feel like the adoption of certain specs / protocols has slowed down over the past couple of years but by the looks of it, things should pick up in a couple of update cycles. I'd rather wait for Intel's 10nm architecture for all the benefits that it'll bring, including LPDDR4X SDRAM support. Also PCIe 5.0 seems to be a given for high-end gaming laptops? I'm assuming motherboard manufacturers for this category will skip 4.0 or jump quickly thereafter to 5.0, assuming Intel's 11th Gen CPUs actually support it by then.

I also prefer to wait for HDMI 2.1 & the upcoming DisplayPort 2.0 to be supported by NVIDIA's next year's GeForce 30 Series GPUs. But more importantly, for the sake of future-proofing and making use of the fastest transfer rates possible, I'd also want to wait for the upcoming USB4 to be supported. The news about Intel making Thunderbolt 3 a royalty-free standard going forward, and providing native support for it in the 10nm CPUs without the need to use a dedicated controller is very encouraging. I think USB Type C ports, with dual support for both Thunderbolt 3 & USB4 (i.e. The Ultimate Port) will be rapidly adopted & become widespread in a couple of years, especially if PCIe 5.0 is implemented by then.

I could be wrong, but realistically, a 2021 time frame seems realistic for all the above specs & protocols to be supported. Thoughts on this?

And regarding the total number of USB ports (both Types A & C), at this point in time the highest number I know of on any mainstream laptop is 5 (3 Type A + 2 Type C), and my hope is that this number will go to at least 6 (3 Type A + 3 Type C or 2 Type A + 4 Type C) by the time PCIe 5.0 is rolled out. I'd love 8 ports (4 of each) on a 17" laptop but I highly doubt it'll happen. I currently use a USB 3.0 data hub with a dedicated power adapter, but a laptop with 6+ USB ports would eliminate my need for one. I'm always on the go & not having to carry a USB data hub would be convenient.

 

[Eximo]

I don't see those specs getting adoption that quickly. Only talking about two or so generations of hardware.

10nm CPUs are already on the design books, even 7nm is ramping up already according to Intel. I think 10nm is going to be a short lived process node for Intel CPUs, they'll probably delegate it to chipset duty or even to Xe production. It has a stigma and it doesn't look competitive to the layman with 7nm process nodes already on the market.

On your last point, you might want to look at some more custom hardware. Check out XoticPC, they carry a wide range of products (many of which are rebranded by MSI, ASUS, Dell, etc as their gaming lineups). They also have laptops that use desktop chipsets which may offer what you are after in terms of ports.

But I still think the trend is going to lean heavily on wireless connectivity and a few powerful multi-purpose ports. WiFi 6 (aka 802.11ax is quite speedy) Also next gen bluetooth to consider. Especially in the category of ultrabooks.

 

[Armani316]

@Eximo Thank you once again for responding. I see your point regarding the quick adoption of all these specs. However, if you look at the release date of each of these latest standards, and the track record of the speed of adoption for previous generations of the same standard, it seems pretty reasonable:

1. 10nm in H-series Intel CPUs: Yes this will be short lived given the current market trends, namely the progress AMD has made. My assumption was that the H-series of 2020's 10th Gen CPUs will be based on the 10nm Ice Lake architecture, but recent leaks have shown that we'll get Comet Lake, yet another 14nm CPU. So either Intel introduces the first H-series 10nm CPUs in 2021 (Ice Lake or Tiger Lake) or jumps straight to 7nm which I definitely won't complain about. I doubt they'll do it that soon though given their recent track record of yield issues & falling behind schedule. But even with that, is there really a possibility of Intel not introducing at least a 10nm H-series lineup by mid 2021? That would be disastrous.

Edit: The following article came out as I was typing this post; a prime example of how fast technology moves nowadays:
https://www.tomshardware.com/news/intel-7nm-10nm-investor-process,39298.html

2. LPDDR4X SDRAM Support: Intel has already made it official that starting with Ice Lake, this RAM standard will be supported, so whenever we get a 10nm H-series lineup, LPDDR4X support will come with it.

3. PCIe 5.0: This is a bit tricky seeing how the standard hasn't been published yet (it's supposedly coming in Q2 2019), and given that it will coexist with PCIe 4.0. From my understanding, PCIe is among the fastest standards in terms of adoption rate, so if it does come out in the next 2 months, wouldn't it be reasonable to assume that 2 years is enough to see it supported by high-end laptops? PCIe 3.0 came out in November 2010, and my August 2012 laptop's motherboard & CPU supported it.

4. HDMI 2.1: This came out November 2017, which was a little too late for it to make its way to NVIDIA's GeForce RTX 20 series. This series currently supports HDMI 2.0b, the one right before HDMI 2.1, so it's safe to assume that the GeForce 30 Series (which will be announced presumably in Q3-Q4 2020) will support it.

5. DisplayPort 2.0: This is the one I'm least certain about. It's not out yet but the specs should be released around June - July 2019 according to VESA. I don't know if that's going to be enough for NVIDIA to support it a year & a half later, and I don't even know what the connector will look like. Will it still be a Mini DisplayPort? Will it adopt USB Type C? I read the bandwidth required for DP 2.0 is 64.8 Gbps. Is USB Type C capable of such high bandwidths given that the latest standards (USB4 & Thunderbolt 3) go only up to 40 Gbps?

6. USB4: This isn't out yet but the specs should be released around mid 2019 according to the USB-IF. Now USB is a little tricky because despite its ubiquity, PC & peripheral makers have historically been super slow in adopting new USB standards. Take the latest standard as an example - USB 3.2 Gen 2x2 @ 20Gbps. The standard came out in September 2017 and yet not a single major laptop manufacturer has a USB Type C port that supports it, despite the recent wave of upgrades to the high-end laptop segment. There's still a chance we might see it in the H2 2019 though. However, seeing how USB4 is a major upgrade, at least from a branding & marketing perspective, and given how Intel made Thunderbolt 3 royalty-free and natively supported in its future CPUs, I think USB4 adoption might be a little quicker. PC makers will race to advertise the inclusion of the Ultimate Port (Thunderbolt 3 & USB4). Also, USB Promoter Group CEO Brad Saunders said that we should expect the standard to start popping up in 12-18 months from its release date, so even if we go with 24 months, mid 2021 sounds like a reasonable target.

Any thoughts on the above points would be appreciated.

With regards to XoticPC, I bought my last laptop from them but didn't have a good experience dealing with them, but I will have a look at their website. As for the wireless technologies, I specifically did not mention them (Wi-Fi 6 & Bluetooth 5) since they're already available and including them in my next laptop is a given. I don't see any major spec updates on the horizon, certainly not within the next 2 years. I did have a look at Bluetooth 5.1 but the minor updates do not concern me & Wi-Fi cards can always be upgraded cheaply as long as the connector is compatible.

 

[Eximo]

The thing with a lot of these standards is increased bandwidth only. So basically you just need components that can switch fast enough. Take AMD's support of PCIe 4.0 already. Unnecessary, but the support is there in the chip, so why not.

In terms of physical connectors for display port, no change. The protocol is already supported in all the form factors you mention, they don't need to adopt anything different. Type-C/Mini for laptops and the full size port for desktops. Mini for specialty cards (6+ display headers)

I have no doubt Nvidia will support the new standards, but I am specifically talking about laptop adoption. That is mostly up to the designer what they hook up to external ports and how fast that port can go. Most people don't need high performance standards.

Memory standards shouldn't be much of a consideration. Whatever platform that has the capabilities you want, well, that is what you get.

As a company XoticPC is basically just a retailer, it is what they sell that is interesting. You can find other sellers. Eurocomp (or Eurocom, I forget), Sager, and a few others that offer less standard hardware.

Wireless techs being on the market and being adopted are two different things. I suspect Apple to lead the way there.

 

[Armani316]

Thanks you for the great discussion, @Eximo

 

[Armani316]

@Eximo I've got a few follow up questions to this topic, if you don't mind.

1. Which exact laptop components need to use PCIe lanes? I understand that all types of ports (USB, HDMI, Mini DisplayPort, Ethernet RJ45, Card Readers, Audio Jack) and other components such as Wi-Fi cards & M.2 SSD slots need PCIe lanes, but is there anything else? Do other components (e.g. RAM, built-in speakers, webcam, built-in display, etc.) need those?

2. Which type of PCIe data (i.e. components) goes to the CPU, and which goes to the chipset?

3. When a CPU model (e.g. Intel Core i9-9980HK) can have a maximum of 16 PCIe lanes, and a compatible chipset (e.g. Intel HM370 Chipset or Intel CM246 Chipset) can have 20 or 24 PCIe lanes, does that mean that the chipset will be restricted to 16 lanes when paired with this CPU model? Or are the two independent from each other in terms of PCIe lanes capability?

To reiterate: These questions are strictly in the context of laptops, not desktops.

Thank you!

 

[Eximo]

The same applies to both desktops and laptops. The technologies are not all that different, just a form factor. In the case of both Intel and AMD, the consumer lineup of CPUs is actually the same architecture. Intel tends to release on mobile before desktop, AMD seems to do it the other way around.

RAM will be connected directly to the CPU's memory controller. It is necessary for operation. (In the past the memory controller was on the chipset I believe)
Speakers will be plugged into the audio card/chipset. The audio solution will run on PCIe.
Webcam will likely be internally connected to USB. The USB controller will be on PCIe.
The display will be connected to the video solution, be it on the CPU or a discrete GPU via PCIe.
Everything else you mentioned will be on the PCIe bus in one way or another.

Typically, connections directly to the CPU are limited to a graphics card(s) and usually a single NVMe storage solution. This is not always the case, sometimes the NVMe storage is exclusively through the chipset.

The chipset has its own PCIe interface. So when they say it provides 24 lanes, it can support that much bandwidth connecting and communicating through it. The chipset is connected to the CPU via DMI, which is usually 4x PCIe lanes equivalent. This limits the total bandwidth between the CPU and the chipset, so running many high bandwidth devices that need to communicate to the CPU/Memory will be slowed down if all need access at the same time.

Chipsets and CPUs haven't always had the same PCIe support level either. There were times when the CPU supported PCIe 3.0 and the chipset only PCIe 2.0. Looks like we are back to that with AMD's latest boards. CPU supports PCIe 4.0 and the chipset 3.0.