I had a failing (SMART) few years old 2tb seagate. I replaced it with a WD Green 5200RPMs (WD20EZRX), cloned with clonezilla. Then later changed it for a refurb Seagate Barracuda 7200RPMs (ST32000641AS) (I believe it's a 4 platter, not the newer 2 platter) again moving data with Clonezilla . Both have 64mb of cache I believe. I use it for most programs and data storage.
When I first installed the Seagate, crystaldiskmark and AS SSD both rated it for sequential read/write in upper 100s (attached to SATA III 6GB/s port). The other day I installed my WD Green as a tertiary data drive (seagate is secondary, ssd is primary). Ran crystal disk mark as AS SSD on both. Was shocked to see the Seagate is now around 95MB/s read/write sequential, whereas the WD Green is 150/140. On the other tests the WD Green was anywhere from 50% to 100% faster.
What's going on? I had about 1TB of data on the barracuda when I installed it and did the first tests. Have since added about 200MB. It's FULLY defragged using mydefrag. The WD Green is blank atm. Would this have anything to do with it? I do'nt see how adding a moderate amount of data to the Seagate would drop its transfer rate so much.
Is it worth it cloning the Seagate to the WD green and using it as my games/data drive, then wipe the Seagate, since the performance difference is so significant?
Why would it have slowed so much?
More about :green 5200 rpm benchmarking faster seagate barracuda 7200rpms
Generally the fastest area on a drive is the outside, which is written to first. It's possible that the Green is reading from there, while the test is a lot further inwards on the Seagate, because there's a lot of stuff around the outside.
Also, random (4K) reads and writes tend to matter a lot more than sequential.
Well the random reads on the WD green are even better than that Seagate..50% to 100%...but that doesn't explain why witj roughly the same amount of data the seagate has dropped so much. So..again..am I better off using the WD Green as my primary data drive?
Yes, it does explain it. More platter goes past the heads near the edge of the drive, compared to the center. Thus, more throughput. The seagate is already half filled, but the Green drive is benchmarking right at the edge. If you filled up the green drive, you'd probably get a worse result.