How To Locate and Remove Personal Computer Bottlenecks

This table can be used to spot the bottlenecks in your computer.
In order to use it, simply list the bandwidths of each protocol used, and the lowest number indicates the bottleneck.

For example, if you connect an external ata/66 (66 MB/s) hard drive via USB v1.1(Burst 1.5MB/s) to a USB PCI v2.1 card (508.6 MB/s) on an FSB PC133 (1.1 GB/s) motherboard.
In this example, USB v1.1 is the bottleneck and moving to USB v2.0 (60 MB/s) would increase the bandwidth by x40.

Bandwidths

	Protocol	Version	Mode	WordSize	Speed	Bandwidth
1	ISA			8	8.3 MHz	7.9 MB/s
2				16		15.9 MB/s
3	EISA			32		31.8 MB/s
4	VLB				33 MHz	127.2 MB/s
5	PCI
6		2.1		64	66 MHz	508.6 MB/s
7	PCI-X
8	AGP			32		254.3 MB/s
9			x2		133 MHz	508.6 MB/s
10			x4		266 MHz	1,017.3 MB/s
11			x8		533 MHz	2.1 GB/s
12	PCIe		x1	1	2.5 Gb/s	250 MB/s
13			x2	2		500 MB/s
14			x4	4		1 GB/s
15			x8	8		2 GB/s
16			x16	16		4 GB/s
17			x32	32		8 GB/s
18	FSB			64	66 MHz	550 MB/s
19		PC100			100 MHz	800 MB/s
20		PC133			133 MHz	1.1 GB/s
21	FSB DDR	DDR200(PC1600)			100 MHz dual	1.6 GB/s
22		DDR266(PC2100)			133 MHz dual	2.1 GB/s
23		DDR333(PC2700)			166 MHz dual	2.7 GB/s
24		DDR400(PC3200)			200 MHz dual	3.2 GB/s
25		DDR433(PC3500)			215 MHz dual	3.4 GB/s
26		DDR466(PC3700)			233 MHz dual	3.7 GB/s
27		DDR500(PC4000)			250 MHz dual	4.0 GB/s
28		DDR533(PC4200)			266 MHz dual	4.3 GB/s
29	FSB DDR2	DDR2-400(PC2-3200)			200 MHz dual	3.2 GB/s
30		DDR2-533(PC2-4200)			266 MHz dual	4.3 GB/s
31		DDR2-667(PC2-5300)			333 MHz dual	5.3 GB/s
32		DDR2-800(PC2-6400)			400 MHz dual	6.4 GB/s
33	ATA	/33		8	16.6 MHz dual	33 MB/s
34		/66			33 MHz dual	66 MB/s
35		/100			50 MHz dual	100 MB/s
36		/133			66 MHz dual	133 MB/s
37	SATA			1	1.5 GHz	150 MB/s
38			II		3.0 GHz	300 MB/s
39	USB	1.1	Control		1.5 Mb/s	188 kB/s
40			Burst		12 Mb/s	1.5 MB/s
41		2.0			480 Mb/s	60 MB/s
42	IEEE 1394				400 Mb/s	50 MB/s
43			b		800 Mb/s	100 MB/s
44	Ethernet	10base-T			10 Mb/s	1.2 MB/s
45		100base-T			100 Mb/s	12.5 MB/s
46		Gigabit			1 Gb/s	125 MB/s
47		10 Gigabit			10 Gb/s	1.25 GB/s
48	WiFi	IEEE 802.11b			11 Mb/s	1.2 MB/s
49		IEEE 802.11a			54 Mb/s	5 MB/s
50		IEEE 802.11g
51		IEEE 802.11n			108 Mb/s	10 MB/s
52	CD-Drive	1x				150 kB/s
53		2x				300 kB/s
54		4x				600 kB/s
55		8x				1.2 MB/s
56		10x				1.5 MB/s
57		12x				1.8 MB/s
58		20x				3.0 MB/s
59		36x				5.4 MB/s
60		40x				6.0 MB/s
61		48x				7.2 MB/s
62		50x				7.5 MB/s
63		52x				7.8 MB/s
64	DVD-Drive	1x				1.35 MB/s
65		2x				2.70 MB/s
66		2.4x				3.17 MB/s
67		3x				4.05 MB/s
68		4x				5.40 MB/s
69		5x				6.75 MB/s
70		8x				10.8 MB/s
71		10x				13.5 MB/s
72		12x				16.2 MB/s
73		16x				21.6 MB/s
74		24x				32.4 MB/s
75	USB	3.0	Burst	1	4.8 Gb/s	600 MB/s

Please e-mail any suggested additions or corrections to this table to data@scarletline.com