Hardware Performance

Question 1

typical HDD seek time

Answer 1

4 - 15 ms [ according to wikipedia as of 2010]

Question 2

Typical SSD seek time

Answer 2

.08 to .15 ms

Question 3

the two categories of hard disk performance characteristics

Answer 3

access time and data transfer time

Question 4

L1 cache reference

Answer 4

1ns

Question 5

Branch mispredict

Answer 5

3ns

Question 6

L2 cache reference

Answer 6

4ns [2020]

Question 7

Mutex lock/unlock

Answer 7

17ns [20ns]

Question 8

Main memory reference

Answer 8

100ns

Question 9

Why were CPU caches invented (I.e l1, l2 etc)?

Answer 9

Cpu speed was improving faster than RAM (DRAM speed), so people invented CPU caches (memory inside that CPU, I.e SRAM to remove the performance bottleneck)

Question 10

Name a top end consumer CPU and L1 cache size in 2021

Answer 10

Intel i9 9980 XE; 1MB L1

Question 11

FSB

Answer 11

a computer communication interface (bus) (front side bus) that was often used in Intel-chip-based computers during the 1990s and 2000s

Question 12

Thermal design power

Answer 12

sometimes called thermal design point, is the maximum amount of heat generated by a computer chip or component that the cooling system in a computer is designed to dissipate under any workload.

Question 13

Typical l2 cache size 2021

Answer 13

256KB to 8MB

Question 14

Max 2021 l3 cache size

Answer 14

32mb for consumer, 64 mb for server

Question 15

Which caches are core specific and which are shared between the cores?

Answer 15

L1 and l2 are core specific. L3 is shared among the cores

Question 16

S3 storage costs

Answer 16

2.3cents/GB/month for frequently accessed items (S3 Standard Tier)

Question 17

When should s3 glacier storage be used?

Answer 17

For long-term data archiving that is accessed once or twice in a year and can be restored within 12 hours

Question 18

S3 glacier costs

Answer 18

.1cent/gb/ month

Question 19

Highest stock clock speed

Answer 19

5.5gHz

Question 20

TDP

Answer 20

Thermal design power

Question 21

L1 cache hits typically have what latency in modern high performance cores [2017]

Answer 21

3 to 4 cycles

Question 22

Why might a program get <1 instruction per cycle?

Answer 22

Hyperthreading, particularly when waiting for a memory fetch

Question 23

L1 cache size

Answer 23

8KB for intel i846 (pre 2012 think)

Question 24

Typical l3 cache size

Answer 24

8MB to 32MB

Question 25

Typical page size

Answer 25

4KB

Question 26

2021 L1 cache size

Answer 26

Modern CPUs include up to 512KB of L1 cache (64KB per core) for flagship processors while server parts feature almost twice as much

Question 27

2021 l2 cache size for flagship CPUs

Answer 27

They range from 4-8MB on flagship CPUs (512KB per core)

Question 28

Why do AMD’s Ryzen CPUs have a much larger cache size compared to rival Intel chips?

Answer 28

because of the MCM design vs Monolithic on the Intel side