Blackmagic Forum

Hi, i have dpx sequences (4k 16bit ) where each frame is 53MB+ in size. So If i want to play back 24fps without drop frame, what is the minimum harddrive speed to handle this task? Can someone share the formula ? do i just simply multiply the number or is there any other factor in the calculation ? i think it's not that simple.

Thanks

Consider a 8 drive raid for this task, fiber channel connected to Resolve

(frame size)*fps*bitdepth*3(as we have RGB channels)/8 (to go from Mbits to Mbytes)
eg.
4096*2160*24*16*3/8=1274Mbytes/sec.

You need steady 1300MBytes/sec for this, so at least 8 HDDs or 3-4xSSDs.

In terms of connections- 10Gbit is not fast enough. You rather need TB3 or 16Gbit+ fibre. TB2 is on border line.

Thanks Andrew for the detail.

Andrew Kolakowski wrote:(frame size)*fps*bitdepth*3(as we have RGB channels)/8 (to go from Mbits to Mbytes)
eg.
4096*2160*24*16*3/8=1274Mbytes/sec.

You need steady 1300MBytes/sec for this, so at least 8 HDDs or 3-4xSSDs.

In terms of connections- 10Gbit is not fast enough. You rather need TB3 or 16Gbit+ fibre. TB2 is on border line.

Awesome man. I will use this as reference . Right now my current setup (personal use) is using 4SSD x2Tb= 8Tb internally on AMD threadripper system. Works fine so far. I just need that formula in case i want to build TB3 HDDs external storage . SSD is expensive if i want to go 32Tb+ then it maybe not a good choice. Since i'm not at corporate class, i would avoid fiber system, i think it need more maintanance and need more addon hardware (correct me if i'm wrong). If you need giant storage capacity and multiple user access , the fiber is fit. But i think for 3Tgb , maybe TB3 is better choice.

Yes, you are correct.
TB3 is good choice for you. It should do around 3GBytes/sec with good enclosure (eg. Areca) and dedicated TB3 port.

Note: if you implement spinning disk rather than SSD, note the bandwidth specs of the individual drives are quoted by the IT industry as the optimum speed.. i.e. empty drives. If they fill the drives from the inside of the platter the random seek speed will become progressively worse as the drives write on outer tracks.

So, will 8 might be technically accurate if the drive bandwidth was consistent based on 'fullness' many drive subsystems for this type of demand are 12 or 16 drive configs.

Just something else to consider.

Yes, you rather need 1.5x margin with HDDs and then still not fill drive above eg 90%.