I've got a couple of WD hard drives: a WD Red Plus 8TB and a WD Blue 8TB. For a while now, I've been thinking they might be using SMR technology since the write speeds on the Blue drive drop to about 80MB/s during larger write operations. Plus, I've noticed some disk activity even when I'm not doing anything on my computer. However, when I check the product pages, it states that both drives are actually CMR. So, which one is it?
4 Answers
Interesting, these datasheets confirm both are CMR. But I still wonder why the long-term write speeds are so much lower than read speeds. I ran some tests with CrystalDiskMark on the Blue, and the sequential speeds were decent at first but dropped after repeated tests.
You might want to check out the WD datasheets for some clarity. There’s a guide that explains how to identify if your drive uses CMR or SMR. It supports the idea that both your drives are CMR.
The WD Red should definitely be CMR. As for the Blue drive, I suspect it's also CMR, but I can't confirm that since I haven't used one before.
I'd trust the info on the WD product pages; they’re usually reliable.
That makes sense! Just out of curiosity, are there other reasons why long write speeds might be slower than reads, even if they're CMR?