Low DMA speed? How to fix a slow DMA card

A slow DMA card is almost never a broken card. It's the link to your second PC: the cable, the USB port, the PCIe slot or a setting. Run the speed test, check the numbers below, then work down this page in order. The first three sections fix most people.

What a normal speed looks like

Our GODLIKE 100T and most DMA cards send data over a USB 3 chip, the FTDI FT601. That link tops out at around 200 MB/s. A faster USB port doesn't raise it.

The speed test in MewTools runs two tests. The speed test counts how many small reads the card does per second, and the throughput test measures big reads in MB/s. You want ACCEPTABLE or better on both, and an overall PASS. Here are the two results from our flashing guide:

• Reads per second matter most.
  Your software reads lots of small bits of memory, not big blocks. Fewer reads a second means ESP that lags behind the game.
• A huge slowest read means dropouts.
  One read taking 20 ms is the link stalling. That's the cable or the port nearly every time.
• Throughput around 20 to 45 MB/s means USB 2 speed.
  The card still shows up and still works, just far too slowly. Something in the chain is USB 2: the cable, the port or a hub.
• Check the failed reads too.
  One or two percent, like in the passing test, is normal. A fast result with lots of failed pages isn't a good result, because a failed read comes back quicker than a real one.

Cold boot first

A normal restart, or waking from sleep, can leave the card half stuck. It still answers, but badly. Shut the main PC down, unplug it at the back, hold the power button for 15 seconds, then start it and test again. Cold boot the main PC first has the steps. Test before you start a game.

1. The cable

• Use the cable from the box.
  Lots of USB-C cables are charging cables with USB 2 wiring inside. The plug looks the same, so you can't tell by looking.
• No extension cables.
  Every extra joint is another place for the link to drop.
• Flip the USB-C plug.
  Turn it over at the card end and test again. It fixes a bad contact more often than you'd think.
• The data port, not JTAG.
  JTAG is only for flashing. The data port is the one furthest from the gold strip if yours isn't labelled.

2. The USB port on your second PC

• A rear port on the motherboard, USB 3 or faster.
  Front and top ports go through a cable inside the case and can cause dropouts. They can work, but the back is more reliable. Never use a hub.
• Give the card its own group of ports.
  Rear ports are split between a few USB controllers. A webcam, a capture card or anything else that streams all the time can share the card's controller and cause stutters. Move the card to a different group of rear ports.
• Device Manager can't tell you the speed.
  It shows FTDI FT601 USB 3.0 Bridge Device even when the link is running at USB 2. The speed test is how you find out.
• Add-in USB cards.
  Some cheap add-in controllers are worse than the ports on the board. If you use one, try a port on the motherboard instead.

3. The PCIe slot on your main PC

• A short x1 slot is plenty.
  DMA cards like ours use one PCIe lane. A bigger slot doesn't make them faster. A stable slot does.
• Watch for shared lanes.
  Some slots share lanes with an M.2 socket and can drop out or run badly when a drive is in it. Which slot to actually pick covers it.
• The slot speed setting.
  Leave the slot on the fastest setting your board offers. Only step it down, one generation at a time, if the card is unstable or doesn't show. Gen1 has less headroom, so don't lower it just in case. The PCIe slot speed shows where it is.
• No riser.
  Put the card straight in a slot. Cheap or long risers cause exactly this kind of trouble.
• Other PCIe devices.
  They can make speeds unreliable. Turn off onboard devices you don't use in the BIOS, like Wi-Fi if you're on a cable.

Above 4G decoding makes no difference, so leave it as it is.

4. Power settings on your second PC

Windows saves power by putting USB ports to sleep, and the card doesn't like it.

Then close what you don't need on the second PC while you play. A second PC stuck at 100% CPU can't keep up with the reads.

5. The software side

• The driver.
  Use the data driver from MewTools: Drivers & Flashing, then Install DATA Driver (FTDI FTD3XX). Don't use one from a driver download site.
• The memory map.
  Slow loading and dropped reads can come from a missing or old memory map. What a memory map is covers when you need one.
• "TINY PCIe TLP algorithm auto-selected".
  Most DMA software is built on LeechCore. When it prints this, it has fallen back to tiny read packets, which are much slower. It usually means the link or the firmware isn't right, so go through the sections above, then tell us in your ticket.
• A software update.
  If your speed dropped the day your software updated, tell your software's support. A bad LeechCore release has broken reads before. If you use Blurred, don't change its connection settings yourself. Ask Blurred in their Discord.

6. The firmware

If the speed test fails on every cable, every rear port and every slot, it's worth looking at the firmware. Open a ticket and send the screenshot. Don't flash firmware you got from anywhere else to test it. Our files are built for your card's DNA ID and only run on your card.

Still slow? What to send us

Open a ticket in our Discord with:

Haven't bought yet and want to know if your PCs will be fast enough? Post them on the support forum.