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Head-to-head · Best Cfexpress Type B Cards

OWC CF Exp B 4.0 512 GB card vs Prograde Iridium CF Exp 4.0 B 800GB card

Which is the better buy? Side-by-side on rating, price, strengths, and watch-outs — with the published ratings we averaged to get there.

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The short answer

OWC CF Exp B 4.0 512 GB card comes out ahead by a clear margin (4.5 vs 3.5). The gap is mostly about video-first hybrid creators — read the strengths below before deciding.

OWC CF Exp B 4.0 512 GB card
Higher ratedRanked #2 in Best Cfexpress Type B Cards
OWC CF Exp B 4.0 512 GB card
3 sourcesall derived$399.99as of Oct 1

The OWC Atlas Pro CFexpress 4.0 Type B memory card delivers exceptional performance with peak write speeds up to 3,000MB/s and read speeds up to 3,650MB/s, making it ideal for professional photographers and filmmakers capturing 6K video or shooting at high frame rates. It offers robust durability against environmental challenges and supports sustained write speeds up to 800MB/s, though its $399.99 price point and requirement for a separate USB4 reader for full performance may deter some users. This card is particularly beneficial for those working with Sony Alpha cameras and other high-end systems that demand fast data throughput.

Strengths
  • — Delivers peak write speeds up to 3,000MB/s and read speeds up to 3,650MB/s
  • — Supports sustained write speeds up to 800MB/s for professional workflows
  • — Durable design resistant to shocks, drops, extreme temperatures, UV rays, and X-rays
Watch-outs
  • — Expensive, priced at $399.99 for the 512GB model
  • — Requires OWC USB4 reader for full speeds, which is not included
$399.99 · Check Price on AmazonFull review →
Prograde Iridium CF Exp 4.0 B 800GB card
Ranked #4 in Best Cfexpress Type B Cards
Prograde Iridium CF Exp 4.0 B 800GB card
5 sources1 derived$799.99as of Oct 1

ProGrade Digital's Iridium CFExpress 4.0 Type B 800GB card delivers exceptional performance with read speeds up to 3550MB/s and write speeds up to 3000MB/s. Thessdreview noted its compatibility with USB 4.0 standard and low power consumption ideal for extended video recording. The card comes with software tools including RefreshPro for sanitization, though performance is optimized when paired with the ProGrade PGM12 reader and a USB 4.0 or Thunderbolt 4/5 port. This makes it a top choice for professional videographers and photographers seeking maximum speed, but users must ensure compatible hardware for peak performance.

Strengths
  • — Achieves up to 3550MB/s read speed and 3000MB/s write speed
  • — Supports USB 4.0 standard for high-speed data transfer
  • — Designed for continuous video recording with low power consumption
Watch-outs
  • — Performance is dependent on using the ProGrade PGM12 USB4 CFExpress B Card Reader
  • — Requires USB 4.0 or Thunderbolt 4/5 PC port for maximum speeds
$799.99 · Check Price on AmazonFull review →

Derived means the reviewer published no score, so one was inferred from their written verdict. Everything else is a number the publisher printed. How we rank.

How they stack up

OWC CF Exp B 4.0 512 GB card

The OWC CF Exp B 4.0 512 GB card delivers peak write speeds up to 3000 MB/s, matching the performance of the ProGrade Iridium card. Its premium pricing at $399.99 makes it less competitive compared to the more affordable Pergear 512GB card.

Prograde Iridium CF Exp 4.0 B 800GB card

The ProGrade Iridium CF Exp 4.0 B 800GB card delivers read speeds up to 3550 MB/s and write speeds up to 3000 MB/s, outperforming the OWC Atlas Ultra's 3650 MB/s read speed and 3000 MB/s write speed, but it requires a ProGrade PGM12 USB4 reader for maximum performance. Its dependency on specific hardware makes it less universally compatible.

Specs side-by-side

SpecOWC CF Exp B 4.0 512 GB cardPrograde Iridium CF Exp 4.0 B 800GB card
Capacity512GB800GB
Read Speed3,650MB/s3550MB/s
Write Speed3,000MB/s3000MB/s
Sustained Write Speedup to 800MB/s1500MB/s
InterfaceCFexpress 4.0CFExpress Type B
Card TypeCFexpress Type BCFexpress Type-B
Warranty3-Year OWC Limited Warranty—
Sustained Write800 MB/s850MB/s
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