I used Delkin Devices 64GB CompactFlash 1050x for years. It cleared the buffer fast enough for sports and didn't cost a fortune compared to the big names.

The 7D II SD slot is limited to UHS-I, so its always the bottleneck during 10fps soccer bursts. In my experience, you have to prioritize the UDMA 7 CF slot for speed.

• ProGrade Digital 128GB CompactFlash Memory Card
• My top pick for reliability. It handles high-speed writes perfectly.
• Transcend 128GB CompactFlash 1000x
• A solid alternative that hits high speeds without breaking the budget. Stick to the CF for your primary and you wont see that busy message again.

Coming back to this after a bit... honestly, you really need to be careful with the 7D II because that SD slot is a total trap for sports. It basically forces the whole camera to slow down to its level. If you have $130, I would suggest putting it all into one or two solid CF cards instead of trying to use both slots.

• SanDisk Extreme 128GB CompactFlash

This one is a classic for a reason. Its super reliable and handles the 10fps bursts without getting hot. Its way more stable than whatever was in your junk drawer, ngl.

• Sony 128GB CompactFlash Memory Card

I've found Sony cards to be incredibly tough. They have very consistent write speeds which is what you need so the buffer clears fast before the next play. Make sure you format the card in the camera before the game starts. It helps keep things running smooth. You're gonna do great at the tournament, just keep that buffer clear!

Man I totally feel your pain. Missing a winning goal because of a blinking light is literally the worst feeling. Since youre shooting soccer, you might want to be careful with the SD slot on that camera. The 7D Mark II is kinda old school and the SD slot is actually way slower than the CF one. Even if you buy a super fast SD card, the camera bottlenecks it and youll still get that busy message during those long bursts. I would suggest picking up a SanDisk Extreme Pro 64GB CompactFlash 160MB/s UDMA 7. It is fast enough to keep up with the 10fps without hitting the wall. Seriously, make sure you get the UDMA 7 version specifically or it wont help much. You could also grab a Lexar Professional 1066x 64GB SDXC UHS-I Silver as a backup, but keep the heavy lifting on the CF card. Better to spend the money now than lose more shots at the tournament!

Z999 is spot on but it's honestly so disappointing how Canon handled the internal architecture on this body. They marketed it for speed but then gimped the SD slot by capping it at UHS-I speeds, which is barely 104MB/s theoretical max. It's basically a legacy bottleneck that ruins the 10fps potential. I've found that even premium SD brands can't save you here because the camera hardware itself is the ceiling. In my experience, comparing high-end CF brands against high-end SD brands in this specific body shows a massive write-speed delta that Canon really should have addressed. UDMA 7 is the only way to go. A couple of things to clarify first tho:

• Are you shooting full RAW or just JPEGs for these soccer games?
• Do you have the cards set to record to both slots at the same time? If you're using the SD slot for backup, the whole system chokes to that slower speed regardless of what CF card you put in the other slot.