In computing, we deal with a large range of orders of magnitude: from individual bits to petabytes of storage, for example.

On this page are two tables of order of magntitude, one for time and one for data sizes, with examples.

Table 1: time scales in computing

time example
10^-9 = 1 ns about one CPU instruction (Intel GHz era); about the time electrical signal in copper wire transmits 0.3 meters
10^-8 = 10 ns about one CPU instruction (486 era)
10^-7 = 100 ns DRAM random read
10^-6 = 1 μs (1000 ns)
10^-5 = 10 μs ping time on localhost
10^-4 = 100 μs ping time on gigabit LAN
10^-3 = 1 ms (1000 μs) ping time on 100 Mbit/s LAN
10^-2 = 10 ms hard disk seek time, Linux kernel context switch
10^-1 = 100 ms ping time across the Internet
100 = 1 s (1000 ms) Linux kernel boot time
101 = 10 s
102 = 100 s (~ 1.5 min)
103 = 1 ks (~ 15 min)
104 = 10 ks (~ 3 hour)
105 = 100 ks (~ 1 day)
106 = 1 Ms (~ 2 weeks)
107 = 10 Ms (~ 4 months)
108 = 100 Ms (~ 3 years)
109 = 1 Gs (~ 30 years) Unix 32-bit time overflow (4 Gs)

Table 2: data sizes in computing

bits bytes example
20 = 1 0.125 B one bit
21 = 2 0.25 B
22 = 4 0.5 B binary coded decimal digit
23 = 8 1 B one byte, one character in ASCII
24 = 16 2 B IP protocol number; microcomputer word size in the 80s
25 = 32 4 B size of IPv 4 address
26 = 64 8 B typical password length
27 = 128 16 B MD5 checksum length, UUID length, size of IPv6 address
28 = 256 32 B X11 protocol event structure
29 = 512 64 B minimum Ethernet frame length
210 = 1024 128 B typical RAM cache line length
211 = 2048 256 B paragraph of text
212 = 4096 512 B hard disk sector
213 = 8192 1 KiB
214 = 16384 2 KiB ISO filesystem sector
215 = 32768 4 KiB memory page, disk allocation unit, page of text
216 = 65536 8 KiB
217 16 KiB
218 32 KiB DVD sector size
219 64 KiB address space for 8-bit CPUs; large memory page
220 128 KiB NAND flash erase block
221 256 KiB
222 512 KiB
223 1 MiB
224 2 MiB large memory page on x86-64 or x86-32 with PAE
225 4 MiB compressed pop song
226 8 MiB
227 16 MiB typical high-end DSLR RAW image file
228 32 MiB
229 64 MiB
230 128 MiB
231 256 MiB
232 512 MiB typical memory size in a smartphone (2011)
233 1 GiB
234 2 GiB cheap USB flash drive (2011)
235 4 GiB single-sided, single-layered DVD
236 8 GiB maximum laptop memory (2011)
237 16 GiB maximum memory for desktop (2011)
238 32 GiB
239 64 GiB
240 128 GiB largest USB flash drive (2011)
241 256 GiB largest SSD disk (2011)
242 512 GiB typical laptop hard disk (2011)
243 1 TiB typical desktop hard disk (2011)
244 2 TiB largest hard disk (2011)
245 4 TiB
246 8 TiB
247 16 TiB
248 32 TiB
249 64 TiB
250 128 TiB
251 256 TiB supercomputer RAM (2011)
252 512 TiB
253 1 PiB
254 2 PiB supercomputer disk space (2011)
255 4 PiB
256 8 PiB
257 16 PiB
258 32 PiB
259 64 PiB
260 128 PiB
261 256 PiB
262 512 PiB
263 1 EiB monthly Internet traffic (2004)
264 2 EiB
265 4 EiB
266 8 EiB
267 16 EiB
268 32 EiB
269 64 EiB
270 128 EiB
271 256 EiB
272 512 EiB
273 1 ZiB
274 2 ZiB
275 4 ZiB
276 8 ZiB
277 16 ZiB
278 32 ZiB
279 64 ZiB
280 128 ZiB
281 256 ZiB
282 512 ZiB
283 1 YiB
284 2 YiB
285 4 YiB
286 8 YiB
287 16 YiB
288 32 YiB
289 64 YiB
290 128 YiB
291 256 YiB
292 512 YiB
293 1024 YiB
294 2048 YiB
295 4096 YiB
296 8192 YiB
297 16384 YiB
298 32768 YiB
299 65536 YiB
2100 131072 YiB
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127

Table 3: Transfer speeds in computing

bits/s example
10 Mbit/s pure paramiko over localhost (Linux, Thinkpad X200s)
250 Mbit/s paramiko+openssh over localhost (Linux, Thinkpad X200s)
400 Mbit/s sftp over localhost (Linux, openssh, Thinkpad X200s)
3 Gbit/s raw speed over localhost (Linux 3.2, Thinkpad X200s)