Blender pen tablet lag, and getting usb 2.0 card.

I have been struggling with the pen pad lag in blender. The lag is so horrible that it almost will not draw grease pencil, or make sculpting strokes. No lag when doing the same with mouse, only the pen pad. It makes all of blender sluggish until it's done reading the pen pad.

I decided to buy a pci usb 2.0 expansion card. I would have gotten 3.0 usb but I lack the mother board slots. And the cards that will fit are really expensive.

I think my pen pad sends too much data for the usb 1.1 hub, and it's been bottle necked. I think blender keeps reading the events no matter what, and my pen pad is giving a steady upload of data from it's memory.

 

Wouldn't surprise me as the theoretical maximum speed for USB 1.1 is 1.5MB/sec. It's good enough for keyboards and mice but not a whole lot else but then there wasn't much else when it came out back in 1998. USB 2.0 is 60MB/sec, USB 3.0 is 625MB/sec, USB 3.1 is 1,250MB/sec and USB 3.2 is 2,500MB/sec.

I'm not surprised. It's almost always more expensive to buy cards for a dying standard because the costs of engineering and manufacturing them have to be made up with fewer sales than new standards which can have the costs spread across a greater number of sales.

That being said there wouldn't have been any point in you buying a USB 3.0 PCI card because the PCI bus itself is too slow to properly handle USB 3.0. Like mentioned above USB 3.0 is 625MB/sec but the PCI bus itself is only 133MB/sec and that's shared between all of the cards. You'd basically be throwing money away for no real boost over USB 2.0.

By the way you can generally get very good deals off of eBay. USB 2.0 PCI is generally $6 with free shipping.

https://www.ebay.com/itm/5-Port-High-Speed-USB-2-0-PCI-Controller-Card-w-NEC-Chip-4-1/131931957505

 

That's where I got my pci card from. I also have an pci-X slot, I will google it's speed in a moment. The pci buss speed explains why I can't find any. But there are some out there to make 3.0 usb. I know they are not fast enough.

This also tells me that those pci-e sata 6gbs cards should not be getting 6gbs.

I look for pci-e x16 cards and also pci-e x8 cards, but I found nothing, only loads of pci-e. I'm long way from being able to upgrade to the next tier computer. Looks like an upgrade is the only way after this pci card. I will not try putting an ssd in it.

Oh about blender. I think if blender would check the time on the event's and drop late ones, it would be smoother. I was poking around the source code and made it skip events, and it made the lag less on the pen tablet. However after drawing about 4 strokes with grease pencil the whole programs grinds to a halt until I close the grease pencil.

 

PCI-e is a completely different story from PCI. At least once you step beyond the lowest tier. A single lane of the oldest gen PCI-e is faster than PCI but still not fast enough for USB 3.0 or SATA, but most cards are not targeting the oldest gen. It's far more common for them to target PCI-e 2.0 (all new gens double the bandwidth of the previous).

A PCI-e 2.0 (single lane) can't handle the full potential of USB 3.0 or SATA III but that said it's more than adequate for HDDs and budget SSDs as neither of these are able to take full advantage of the port. It's only once you step into non-budget SSDs (Samsung EVOs and Crucial MXs) with sequential access that you start seeing it happen and even then it's only slightly behind.

A PCI-e 2.0 (four lane) card though can handle three USB 3.0 and two SATA III. You'll frequently see them with more though because it's not common to run all of the ports at full performance all of the time. Once you need that you're stepping into server card territory.

Additionally it's important to understand that the full advertised performance of an SSD is only for times when it's reading and writing large sequential files. An SSD will spend the majority of its time in random mode and frequently at a queue depth of Q4T4 or less.

A 4K chunk Q4T4 benchmark is slower than the advertised speed. Below is a video showing it off (hopefully it starts at the correct time) and even the fastest SATA SSDs don't hit more than 350MB/sec read and write, but that's still many times faster than the HDD. Up to about 200 times in the case of the Samsung EVO.

Spoiler

A 4K chunk Q1T1 benchmark is even slower and can be typical for normal every day activities like light gaming, browsing the web, and so on. Below is the same video with the correct starting point and you might notice that none of the drives go beyond 40MB/sec read and 125MB/sec write. Yet they're still up to about 50 times faster than the HDD.

Spoiler

Basically you'll always see a massive performance improvement upgrading from an HDD to an SSD.

 

I discovered that a pci-e x1 card can fit in a x8 or x16 slot. It will only use x1 lane however. My pci-e x16 slots are version 2.0, and so are my x8 slots. I decided to not fill that slot with 3.0 usb because my pen pad is usb 2.0. The pen pad is my only requirement. I decided to buy the sata 3.0 pci-e x1 card before I looked at your post. I have a 3.0 sata seagate barracuda drive. Currently my computer has 2.0 sata on board. The wiki said that the pic-e x1 slot will take up a lane o the board even though it's equiped with two slots. My video card will have to share with it, if I decide to install it.

 

My problem is solved. After the ubuntu repositories went down I switched to OpenSuse Tumbleweed. I have never seen blender work so fast before. There is no lag with the pen pad anymore. The usb ports are still showing as version 1.1

 

Wow!