Cache Sizes

2003-12-05, 08:26

I was just checking my L 1 and 2 cache sizes, should i be worried that my L1 is only 8kb whereas my L2 is 512?

TauCeti · 2003-12-05, 08:39

No need to worry. That is perfectly normal for your Pentium-4. More information here: Intel Pentium 4 - Product Overview

optim · 2003-12-05, 19:01

L1 cache is always smaller than L2. The reason for this is cost: L1 is more expensive than L2.

Pentium4 CPUs have 8K L1 and 512K L2. Newer versions have 1MB L2.

AMD Athlon CPUs have 128K L1 and 512K L2. Newer 64bit version have 1MB L2.

L1 cache is better and faster than L2, meaning that a CPU with more L1 cache is preferred. L2 cache is also important, but not more important than L1 cache.

There are also some CPUs that have L3 cache, like Pentium 4 Extreme Edition with 2MB L3 cache. L3 cache is slower than L2 cache.

Prime95 "asks" the CPU for some of its properties like L1/L2 sizes and speed (MHz) and displays it on your screen.

QuintLeo · 2003-12-06, 04:11

Depends on the Athlon - the Barton varient has 512K cache, the older Thoroughbred Palomino and Thunderbird varients have 256K.

Also, the Athlon has an "additive" cache - basically, anything in the L1 cache is NOT kept in the L2 cache, which makes their effective cache size larger. The P4 cache design duplicated the data in the L1 cache in the L2 cache, so L2 cache sizes between a Athlon and a P4 are NOT directly comparable.

dsouza123 · 2003-12-06, 13:43

The pre Thunderbird Athlons (slotted) had 512K caches at about half the clock speed (various fractions) of the CPU.

The Thunderbirds have 128K L1 and 256K L2 non duplicating giving 384K total. The L1 is 64K instruction and 64K data.

2003-12-05, 08:26	#1
Unregistered 2²·3²·13·19 Posts	Cache Sizes I was just checking my L 1 and 2 cache sizes, should i be worried that my L1 is only 8kb whereas my L2 is 512?

2003-12-05, 19:01	#3
optim Nov 2003 European Union 1101000₂ Posts	L1 cache is always smaller than L2. The reason for this is cost: L1 is more expensive than L2. Pentium4 CPUs have 8K L1 and 512K L2. Newer versions have 1MB L2. AMD Athlon CPUs have 128K L1 and 512K L2. Newer 64bit version have 1MB L2. L1 cache is better and faster than L2, meaning that a CPU with more L1 cache is preferred. L2 cache is also important, but not more important than L1 cache. There are also some CPUs that have L3 cache, like Pentium 4 Extreme Edition with 2MB L3 cache. L3 cache is slower than L2 cache. Prime95 "asks" the CPU for some of its properties like L1/L2 sizes and speed (MHz) and displays it on your screen. Last fiddled with by optim on 2003-12-05 at 19:03

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2003-12-05, 08:39	#2
TauCeti Mar 2003 Braunschweig, Germany 342₈ Posts	No need to worry. That is perfectly normal for your Pentium-4. More information here: Intel Pentium 4 - Product Overview

2003-12-06, 04:11	#4
QuintLeo Oct 2002 Lost in the hills of Iowa 1C0₁₆ Posts	Depends on the Athlon - the Barton varient has 512K cache, the older Thoroughbred Palomino and Thunderbird varients have 256K. Also, the Athlon has an "additive" cache - basically, anything in the L1 cache is NOT kept in the L2 cache, which makes their effective cache size larger. The P4 cache design duplicated the data in the L1 cache in the L2 cache, so L2 cache sizes between a Athlon and a P4 are NOT directly comparable.

2003-12-06, 13:43	#5
dsouza123 Sep 2002 1226₈ Posts	The pre Thunderbird Athlons (slotted) had 512K caches at about half the clock speed (various fractions) of the CPU. The Thunderbirds have 128K L1 and 256K L2 non duplicating giving 384K total. The L1 is 64K instruction and 64K data.