SD card: 512 blocks limit. Опции

[pitt]

Sorry for using English - I don't have russian keyboard.
Here is my problem: I'm writing blocks 512 bytes each on consecutive sectors of SDHC card. Hardware is STM3240G-EVAL. No file system, no OS no interrupts except SDIO and DMA serving SDIO. The goal is to test the software and measure my access speed: average and lowest. When I'm writing 256 blocks(CMD25) at a time loop of 1000 times I don't have issues except sometimes(5%) access time is more than 10 times greater than average. Don't know why but it is. When I'm writing 512 blocks Average speed is the same but lowest is almost 20 times above average. And the last thing: as soon as I'm trying to write >512 blocks I'm getting instantly FEIF...
Please share your thoughts and knowledge.

Thank you in advance.

Google translator:
Вот моя проблема: я пишу блоки 512 байт каждый на подряд секторов SDHC карты. Аппаратное STM3240G-EVAL. Нет файловая система, нет ОС нет прерывания кроме SDIO и DMA служащая для SDIO.Целью является для тестирования программного обеспечения и измерения мою скорость доступа: средний и низкий. Когда я пишу 256 блоков (CMD25) в петле времени в 1000 раз меня нет проблем, кроме иногда(5%) время доступа более чем в 10 раз больше, чем в среднем. Не знаю почему, но это так. Когда я пишу 512 блоков Средняя скорость же, но низкая почти в 20 раз выше среднего. И последнее: как только я пытаюсь написать> 512 блоков я получаю мгновенно FEIF ...
Пожалуйста, поделитесь своими мыслями и знаниями.

[Dr.Alex]

sometimes(5%) access time is more than 10 times greater than average.

I guess it is normal.
I did not ever bother to test access time for each of that small blocks because I needed *highest* possible write speed which is achievable with BIG chunks only (got over 100 Mbps with regular class-10 or UHS-I cards).

And the last thing: as soon as I'm trying to write >512 blocks I'm getting instantly FEIF...

You'd better try STMcube HAL. It works (with some issues time to time discussed here).
Also you can try Chibios alone with its HAL.