{"id":29988,"date":"2025-08-26T12:19:09","date_gmt":"2025-08-26T08:19:09","guid":{"rendered":"https:\/\/droneandcam.com\/post\/sony-a7r-iii-sd-cards-optimal-uhs-ii-speed\/"},"modified":"2026-02-15T02:37:50","modified_gmt":"2026-02-14T22:37:50","slug":"sony-a7r-iii-sd-cards-optimal-uhs-ii-speed","status":"publish","type":"post","link":"https:\/\/droneandcam.com\/en\/post\/sony-a7r-iii-sd-cards-optimal-uhs-ii-speed\/","title":{"rendered":"Sony A7R III SD cards: optimal UHS-II speed"},"content":{"rendered":"\n

Have you ever spent hours searching for THE perfect SD card<\/a> for your Sony A7R III, getting lost between UHS-II, SDXC, and write speeds? Let’s be honest, choosing the right memory for a camera as demanding as the Alpha 7R III is a real headache, especially when you want to avoid slowdowns during bursts or cutouts during 4K recording. In this guide, we analyze compatibilities, compare key speeds, and recommend tried-and-tested cards<\/strong> to fully exploit your camera’s capabilities without compromise. <\/p>\n\n

\n\n\n\n\n\n\n\n\n\n
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\n \"SanDisk\n

SanDisk 512 GB Extreme PRO<\/h3>\n

Rating: 4.8\/5<\/p>\n

\n \u2605 \u2605 \u2605 \u2605 \u2605\n <\/div>\n Buy on Amazon<\/a>\n<\/div>\n\n\n
\n \"Lexar\n

Lexar 512 GB SILVER PRO<\/h3>\n

Rating: 4.6\/5<\/p>\n

\n \u2605 \u2605 \u2605 \u2605 \u2605\n <\/div>\n Buy on Amazon<\/a>\n<\/div>\n\n\n
\n \"Gigastone\n

Gigastone SDXC 256 GB card<\/h3>\n

Rating: 4.7\/5<\/p>\n

\n \u2605 \u2605 \u2605 \u2605 \u2605\n <\/div>\n Buy on Amazon<\/a>\n<\/div>\n\n<\/div>\n\n\n\n<\/div>\n\n

Memory card compatibility with the Sony a7R III<\/h2>\n\n

The Sony a7R III offers two SD slots: slot 1 is UHS-II compatible (maximum speed ~128MB\/s) and slot 2 is UHS-I compatible (~75MB\/s). Slot 1 provides optimal performance, while slot 2 is suitable for JPEG or backup storage. Use slot 1 to fully utilize your camera’s power<\/strong> . <\/p>\n\n

\n\n\n\n \n \n \n @keyframes clignote {\n 0% { background-color: #ff3b3b; }\n 50% { background-color: #e60000; }\n 100% { background-color: #ff3b3b; }\n }\n\n .widget-container {\n max-width: 100%;\n background: #ffffff;\n border-radius: 16px;\n box-shadow: 0 0 12px rgba(0, 0, 0, 0.08);\n padding: 20px;\n font-family: Arial, sans-serif;\n margin: 0 auto;\n text-align: center;\n }\n\n .promo-banner {\n background-color: #ff3b3b;\n color: white;\n padding: 10px;\n border-radius: 10px;\n font-size: 18px;\n font-weight: bold;\n margin-bottom: 20px;\n }\n\n .product-image {\n width: 80%;\n max-width: 400px;\n border-radius: 10px;\n margin-bottom: 15px;\n }\n\n .buy-button {\n display: inline-block;\n margin-top: 15px;\n padding: 15px 30px;\n background-color: #ff3b3b;\n color: white;\n font-size: 18px;\n font-weight: bold;\n border: none;\n border-radius: 10px;\n cursor: pointer;\n animation: clignote 1s infinite;\n text-decoration: none;\n }\n\n .countdown {\n font-size: 18px;\n font-weight: bold;\n margin-top: 10px;\n }\n \n\n\n \n
\n
\ud83d\udd25 Current promotional offer \u2013 ends in loading…<\/span><\/div>\n \"Sony\n

Sony Alpha 7 R III<\/h2>\n

42.4 MP Full Frame Mirrorless Camera \u2022 4K HDR Video \u2022 3″ LCD Screen \u2022 Eye Tracking \u2022 Long Battery Life<\/p>\n

<\/div>\n
\ud83d\uded2 Buy<\/span><\/div>\n <\/div>\n <\/a>\n\n \n function startCountdown(durationInHours) {\n const countdownElement = document.getElementById(‘countdown’);\n const endTime = new Date().getTime() + durationInHours * 60 * 60 * 1000;\n\n function updateCountdown() {\n const now = new Date().getTime();\n const distance = endTime – now;\n\n if (distance <= 0) {\n countdownElement.textContent = "offre expir\u00e9e";\n return;\n }\n\n const hours = Math.floor((distance % (1000 * 60 * 60 * 24)) \/ (1000 * 60 * 60));\n const minutes = Math.floor((distance % (1000 * 60 * 60)) \/ (1000 * 60));\n const seconds = Math.floor((distance % (1000 * 60)) \/ 1000);\n\n countdownElement.textContent = `${hours}h ${minutes}m ${seconds}s`;\n requestAnimationFrame(updateCountdown);\n }\n\n updateCountdown();\n }\n\n startCountdown(6); \/\/ Compte \u00e0 rebours de 6 heures\n \n\n\n<\/div>\n\n

The UHS-II slot is a plus for burst shooting or 4K video. It reduces buffer flush time, preventing slowdowns. Using a V90 card, you can achieve stable write speeds of 90MB\/s, ideal for large RAW files. Without it, you’ll quickly run into a freeze<\/strong> . <\/p>\n\n

Comparing the technical specifications of the Sony a7R III’s UHS-II and UHS-I slots to optimize storage performance<\/h3>\n\n
Characteristic<\/td>Slot 1 (UHS-II)<\/td>Slot 2 (UHS-I)<\/td><\/tr>
Speed standard<\/td>UHS-II (dual pin set)<\/td>UHS-I (single pin set)<\/td><\/tr>
Maximum write speed<\/td>Up to ~128MB\/s (V90 cards)<\/td>Up to ~75MB\/s (V30 cards)<\/td><\/tr>
Maximum reading speed<\/td>Up to 300 MB\/s (theoretical)<\/td>Up to 170 MB\/s (advertised)<\/td><\/tr>
Maximum Video Speed Class<\/td>V90 (90 MB\/s guaranteed)<\/td>V30 (30 MB\/s guaranteed)<\/td><\/tr>
Impact on buffer flushing<\/td>Optimal speed for bursts<\/td>Emptying time approximately doubled<\/td><\/tr>
Optimal use<\/td>RAW formats and 4K videos<\/td>Secondary or JPEG backup<\/td><\/tr>
Backward compatibility<\/td>Accepts UHS-I (reduced speed)<\/td>Accepts UHS-II (limited speed)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n

Both slots accept all SD cards<\/a>, but the UHS-II slot takes full advantage of UHS-II speeds. A UHS-I card in slot 1 works, but not more than 75MB\/s. For performance, opt for a UHS-II in slot 1 and an affordable UHS-I<\/strong> for slot 2. <\/p>\n\n

Using a UHS-II card in slot 2 will limit its speed to ~75 MB\/s. Conversely, a UHS-I in slot 1 can still be used, but without reaching 128 MB\/s. To optimize, reserve fast cards for slot 1 and economical models for slot 2. This avoids bottlenecks<\/strong> . <\/p>\n\n

\"Sony
Sony a7R III UHS-II and UHS-I slots<\/figcaption><\/figure>\n\n

Importance of write speed for performance<\/h2>\n\n

Write speed is more critical than read speed for burst shooting. It determines how the buffer is flushed to the card. A slow card will freeze the shot after a few shots. For RAW, aim for stable speeds above 90MB\/s<\/strong> . Otherwise, you’ll be slowed down quickly. <\/p>\n\n

The buffer stores images before they are written to the card. The Sony a7R III handles 28 uncompressed RAWs before saturation. A fast card clears this cache in a few seconds, while a UHS-I card takes twice as long. Without sufficient speed, the frame rate drops sharply<\/strong> . This is a crucial point not to be overlooked. <\/p>\n\n