For the Canon 90D, a V60 card is definitely the sweet spot. The camera shoots 4K video at 120Mbps, demanding only 15MB/s write speed, so a V30 technically handles the video. However, since you shoot track days at 10fps, quickly clearing the buffer is where the UHS-II slot shines.

I highly recommend the ProGrade Digital V60 or SanDisk Extreme Pro. A V90 card is overkill for the 90D. It will not give you a noticeable performance boost to justify the massive price jump over a V60. Save that extra cash for a new lens or more track time!

Seconding the recommendation above! If you wanna save some cash, check out the Kingston Canvas React Plus 128GB SDXC UHS-II V90. I've been using one and I'm honestly sooo satisfied with how it handles bursts compared to my old cards. It highkey clears the buffer in seconds... basically makes the 90D feel like a new camera. gl!

For your situation, I would suggest making the jump to UHS-II. UHS-I cards just cant keep up with sports. I use Lexar Professional 1667x 128GB SDXC UHS-II V60. gl!

Regarding what #7 said about "Lewis is totally right about the V60 cards..." - he is spot on. I've run some tests and the 90D bus really tops out around 100 to 110MB/s for sustained writes. You might want to consider the Sabrent Rocket V60 SDXC UHS-II 128GB as a solid alternative. I would suggest being careful with some of the older Lexar cards because their quality control has been a bit hit or miss lately imo. Make sure to check the actual sustained write speeds, not just the peak burst numbers on the box. Since you're doing 4K and track bursts, a high-quality V60 is gonna give you the same real-world performance as a V90 but for way less money. Ngl, it is super easy to overspend on storage you cant even fully utilize. Just watch out for fakes if you are buying from big marketplaces... always run a speed test on your PC before you trust it with your once-in-a-lifetime track day shots!

Honestly, if you're doing sports and birds with those massive 32.5MP RAW files, you 100% need to stick to UHS-II - trying to save money with a "high-end" UHS-I card is just going to lead to more frustration tbh. I've spent way too much time looking at write speed benchmarks for my own 90D and the difference is night and day. While SanDisk is the industry standard, I've found that the SanDisk Extreme Pro UHS-II (300MB/s) carries a bit of a "brand tax" that isn't always worth it. If you want better value from a market-research perspective, I'd look at the ProGrade Digital SDXC UHS-II V60 Gold series. ProGrade was started by ex-Lexar execs and their cards are super consistent... basically designed for high-bitrate work without the premium price of the V90 cards. Another one to consider is the Sony SF-M Tough Series UHS-II. They are physically rugged - wait no, like actually indestructible - which is great for outdoor birding. From a technical standpoint, the V60 rating on these is the sweet spot for the 90D; it clears the buffer fast enough that you rarely hit that wall, even during a long sequence!!! Definitely worth the investment to actually use the 10fps you paid for.

Like someone mentioned, you really need to jump to UHS-II to make that 90D buffer usable. I have been using these for a long time and unfortunately, I've had issues with some of the more popular consumer cards lately. They are simply not as good as expected when you're dealing with the massive 32.5MP file sizes.

• ProGrade Digital SDXC UHS-II V60 Gold provides much better sustained write consistency than the standard retail stuff.
• Angelbird AV Pro SD MK2 V60 is a great choice if you're struggling with those 4K video drops. Methodically speaking, the bus speed on UHS-I is the literal physical bottleneck here. It is disappointing that you have to shell out more for cards, but it is the only way to stop that busy light from hanging forever. Basically, skip the UHS-I pro versions... they're a waste of time for sports.

Same here!

Lewis is totally right about the V60 cards being the sweet spot. I've been using the 90D since it launched and spent way too much time testing different brands for wildlife and sports. V90 is definitely overkill for this sensor because the camera's internal bus hits its limit way before the card does anyway. In my experience, you should look at these if the ones mentioned above aren't in stock:

• Sony SF-M Series UHS-II V60 128GB - it's basically a budget version of the Tough cards but still has the speed you need for those 32.5MP RAW bursts.
• Delkin Devices Power SDXC UHS-II V60 - these have been rock solid for me for years and they're usually a bit cheaper than the big name brands. Dont overthink it too much. Just make sure you're actually getting a UHS-II card with the double row of pins on the back... you'll notice the difference immediately when that buffer starts clearing after a heavy burst of track action. Basically makes the camera actually usable for high-speed stuff.

Saved for later, ty!