5 ms·

“Never underestimate the bandwidth of a station wagon filled with magtape, or a 747 filled with CD-ROMs.”

TeHCrAzY 16y ago
Reminds me of an interesting article re. the bandwidth of a station wagon: http://www.dansdata.com/gz105.htm http://www.dansdata.com/gz105.htm
crsmith 16y ago
Or pigeon http://www.zdnet.com/blog/btl/in-south-africa-carrier-pigeon-faster-than-broadband/24093 http://www.zdnet.com/blog/btl/in-south-africa-carrier-pigeon...
- sjs 16y ago
  A USB stick? How do they interoperate if they don't follow the spec[1]?!! [1] http://tools.ietf.org/html/rfc1149 http://tools.ietf.org/html/rfc1149
pjscott 16y ago
Or a shipping container filled with hard drives. Conservatively speaking, you could easily get more than 60 PB in a typical shipping container and have plenty of room left over for padding, using 3.5" 2 TB hard drives. Assume it takes a leisurely week to get from, say, one coast of the US to the other; that's a little over 100 Gbit/s sustained throughput. I've been rounding down here; the real bandwidth would be quite a bit higher.
- Retric 16y ago
  Last I checked 32 micro SD cards had the highest memory density. http://www.sandisk.com/products/mobile-memory-products/sandisk-microsdhc http://www.sandisk.com/products/mobile-memory-products/sandi... 32GB Micro SD = 1 mm * 11 mm * 15 mm = ~6 million / m^3. So 32GB * 6,000,000 ~= 192 PB per m^3. 2TB 3.5 inch HDD = (4 in × 1 in × 5.75 in = ~3000 / m^3. So 3,000 * 2TB = ~6 PB per m^3 PS: Granted that m^3 if SD cards would cost around 1.2 billion and would take a while to upload at the other end.
  - spicyj 16y ago
    I looked incredulously at your dimensions of the 3.5 inch HDD, only to search for the correct ones and found the exact same specs on Wikipedia, then realizing that's probably where you got yours. Looking at hard drive manufacturers' sites, I see that that is in fact the correct dimensions. What does the 3.5 inch figure represent, then? The size of the plates?
    - c3o 16y ago
      The 3.5 inch figure represents the floppy, remember that? :) A "3.5in HDD" is a hard disk that fits into the bay originally designed to hold a drive for 3.5" floppy disks.
      - chancho 16y ago
        So then why are laptop hard drives called 2.5in?
        SamReidHughes 16y ago
        Because they're smaller.
        plorkyeran 16y ago
        Because 2.4" sounds worse. (3.5 * 69.9 / 102 = 2.3985)
      - megablast 16y ago
        I thought it wass due to the fact that the platters are 3.5", just as the 2.5" hd has 2.5" size platters. But no, looked it up, 3.5" have platter sizes of 3.74" apparently, 5.25" had 5.12" platters. Which makes sense when you look at a hdd with the top off.
- spicyj 16y ago
  Or you could stuff more than one container on a boat. The Emma Mærsk, one of the largest ships, has over 420,000 m^3 of space, which could hold 81 ZB (8.1 million PB) if Retric's (sibling) comment is correct, moving data at just over 1 Eb (exabit) per second. According to Wolfram Alpha, that's big enough to hold the entirety of human knowledge 7000 times.
- rdtsc 16y ago
  If you have to copy to the hard drives and copy from the hard drives on the other end, you might be limited to the total IO bandwidth of however many hard drives you can read/write * speed of IO bus. Not too long ago I had realized that my 1Gbps Ethernet network lets me have a higher sustain data throughput than my 5400 rpm laptop hard drive. You would have the same problem with the crate of hard drives depending how many times you have to copy the data...
  - gaius 16y ago
    Yep, in practice your HDs would be in NetApp shelves or equivalent, and you would also need to account for the volume of the NetApp heads. That reduces the density by 5-10x. Then there is also the overhead of RAID-DP. Still, that's a shitload of bandwidth.
crististm 16y ago
but what about the latency?

Reminds me of an interesting article re. the bandwidth of a station wagon: http://www.dansdata.com/gz105.htm http://www.dansdata.com/gz105.htm

crsmith 16y ago

Or pigeon http://www.zdnet.com/blog/btl/in-south-africa-carrier-pigeon-faster-than-broadband/24093 http://www.zdnet.com/blog/btl/in-south-africa-carrier-pigeon...

sjs 16y ago
A USB stick? How do they interoperate if they don't follow the spec[1]?!! [1] http://tools.ietf.org/html/rfc1149 http://tools.ietf.org/html/rfc1149

pjscott 16y ago

Or a shipping container filled with hard drives. Conservatively speaking, you could easily get more than 60 PB in a typical shipping container and have plenty of room left over for padding, using 3.5" 2 TB hard drives. Assume it takes a leisurely week to get from, say, one coast of the US to the other; that's a little over 100 Gbit/s sustained throughput. I've been rounding down here; the real bandwidth would be quite a bit higher.

Retric 16y ago
Last I checked 32 micro SD cards had the highest memory density. http://www.sandisk.com/products/mobile-memory-products/sandisk-microsdhc http://www.sandisk.com/products/mobile-memory-products/sandi... 32GB Micro SD = 1 mm * 11 mm * 15 mm = ~6 million / m^3. So 32GB * 6,000,000 ~= 192 PB per m^3. 2TB 3.5 inch HDD = (4 in × 1 in × 5.75 in = ~3000 / m^3. So 3,000 * 2TB = ~6 PB per m^3 PS: Granted that m^3 if SD cards would cost around 1.2 billion and would take a while to upload at the other end.
- spicyj 16y ago
  I looked incredulously at your dimensions of the 3.5 inch HDD, only to search for the correct ones and found the exact same specs on Wikipedia, then realizing that's probably where you got yours. Looking at hard drive manufacturers' sites, I see that that is in fact the correct dimensions. What does the 3.5 inch figure represent, then? The size of the plates?
  - c3o 16y ago
    The 3.5 inch figure represents the floppy, remember that? :) A "3.5in HDD" is a hard disk that fits into the bay originally designed to hold a drive for 3.5" floppy disks.
    - chancho 16y ago
      So then why are laptop hard drives called 2.5in?
      - SamReidHughes 16y ago
        Because they're smaller.
      - plorkyeran 16y ago
        Because 2.4" sounds worse. (3.5 * 69.9 / 102 = 2.3985)
    - megablast 16y ago
      I thought it wass due to the fact that the platters are 3.5", just as the 2.5" hd has 2.5" size platters. But no, looked it up, 3.5" have platter sizes of 3.74" apparently, 5.25" had 5.12" platters. Which makes sense when you look at a hdd with the top off.
spicyj 16y ago
Or you could stuff more than one container on a boat. The Emma Mærsk, one of the largest ships, has over 420,000 m^3 of space, which could hold 81 ZB (8.1 million PB) if Retric's (sibling) comment is correct, moving data at just over 1 Eb (exabit) per second. According to Wolfram Alpha, that's big enough to hold the entirety of human knowledge 7000 times.
rdtsc 16y ago
If you have to copy to the hard drives and copy from the hard drives on the other end, you might be limited to the total IO bandwidth of however many hard drives you can read/write * speed of IO bus. Not too long ago I had realized that my 1Gbps Ethernet network lets me have a higher sustain data throughput than my 5400 rpm laptop hard drive. You would have the same problem with the crate of hard drives depending how many times you have to copy the data...
- gaius 16y ago
  Yep, in practice your HDs would be in NetApp shelves or equivalent, and you would also need to account for the volume of the NetApp heads. That reduces the density by 5-10x. Then there is also the overhead of RAID-DP. Still, that's a shitload of bandwidth.

crististm 16y ago

but what about the latency?