We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is L3 Cache?

By R. Kayne
Updated May 16, 2024
Our promise to you
EasyTechJunkie is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At EasyTechJunkie, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

Level 3 or L3 cache is specialized memory that works hand-in-hand with L1 and L2 cache to improve computer performance. L1, L2 and L3 cache are computer processing unit (CPU) caches, verses other types of caches in the system such as hard disk cache. CPU cache caters to the needs of the microprocessor by anticipating data requests so that processing instructions are provided without delay. CPU cache is faster than random access memory (RAM), and is designed to prevent bottlenecks in performance.

When a request is made of the system the CPU requires instructions for executing that request. The CPU works many times faster than system RAM, so to cut down on delays, L1 cache has bits of data at the ready that it anticipates will be needed. L1 cache is very small, which allows it to be very fast. If the instructions aren’t present in L1 cache, the CPU checks L2, a slightly larger pool of cache, with a little longer latency. With each cache miss it looks to the next level of cache. L3 cache can be far larger than L1 and L2, and even though it’s also slower, it’s still a lot faster than fetching from RAM.

Assuming the needed instructions are found in L3 cache (a cache hit), bits of data might be evicted from L1 cache to hold the new instructions in case they’re needed again. L3 cache can then remove that line of instructions since it now resides in another cache (referred to as exclusive cache), or it might hang on to a copy (referred to as inclusive cache), depending on the design of the CPU.

For example, in November 2008 AMD® released their quad-core Shanghai chip. Each core has its own L1 and L2 caches, but the cores share a common L3 cache. L3 keeps copies of requested items in case a different core makes a subsequent request.

The architecture for multi-level cache continues to evolve. L1 cache used to be external to the CPU, built into the motherboard, but now both L1 and L2 caches are commonly incorporated into the CPU die. L3 cache has typically been built into the motherboard, but some CPU models are already incorporating L3 cache. The advantage of having on-board cache is that it’s faster, more efficient and less expensive than placing separate cache on the motherboard.

Fetching instructions from cache is faster than calling upon system RAM, and a good cache design greatly improves system performance. Cache design and strategy will be different on various motherboards and CPUs, but all else being equal, more cache is better.

EasyTechJunkie is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
By anon969718 — On Sep 12, 2014

The main problem is than windows is not using this second level data cache download cpu-z looking about your cache open regedit path hklm/system/currentcontrolset/control/sessionmanager/memorymanagement

search dword key secondleveldatacache edit if you have 512 edit 0x00000200 hexadecimal

By anon952595 — On May 21, 2014

The writer needs to explicitly happens when "bits of data are evicted from L1 cache" Where do those bits go? I assume the L3 cache since it has gone through 1 and 2L cache. The article seems to overly simplify a couple of things, but for the most part reads well

By anon951182 — On May 14, 2014

Is there a system configuration report that can show me my levels of ram on my pc (running XP)?

By anon290142 — On Sep 07, 2012

Is it possible that one day ram and the cpu will come in one unit?

I briefly heard about quantum entanglement the other day. Perhaps that will come into play with speeding up data retrieval and manipulation from the ram.

By elgun — On Feb 22, 2012

Please help me. I have an l3 cache on my motherboard (as internal hardware). Which model motherboard do I have?

By anon162544 — On Mar 24, 2011

My Phenom II x2 3.1ghz processor has 6mb of L3 cache and a TDP rating of 80w. I looked at the specs for a 3.1ghz Athlon II processor. The specs look the same, except for no L3 cache and a TDP rating of only 65w. Does this mean the L3 cache uses a power hungry 15w? Aye Caramba!

By anon149631 — On Feb 05, 2011

My PC Only has 512kb of L2 cache.

By anon147839 — On Jan 30, 2011

You know, when you define something, you're not supposed to use the word you're defining to define it.

By anon138824 — On Jan 02, 2011

wow this was the first hit and i learned something new. thank you.

By Gerry — On Dec 24, 2010

Simply excellent

By anon133227 — On Dec 09, 2010

CPU is central processing unit. not computer processing unit. but otherwise, great info!

By anon129012 — On Nov 21, 2010

Thank you, it's what i wanted to know. Now on seeing that L3 cache cost more to get on a cpu, who would be more suited to needing L3?

By anon120453 — On Oct 21, 2010

lovely, short and crisp definition.helped me figure out what l3 meant. thank you. -- dhira

By anon118470 — On Oct 14, 2010

Nice job. I tried to find out what L3 cache was a few months ago, but couldn't find an easy explanation. This article is very easy to understand. Thanks.

By anon105698 — On Aug 22, 2010

nice nice, easy to understand and i finally know what L3 cache is. Thanks for the easy info!

By anon100240 — On Jul 29, 2010

Good article. Thank you!

By anon96250 — On Jul 15, 2010

Very good article. The author has used simple words to present a complex matter in layman's terms. Easy to understand even for a newbie like me. Well done.

By anon94741 — On Jul 09, 2010

thanks. this information is really worthy.

By anon86774 — On May 26, 2010

Thank you!

By anon86134 — On May 24, 2010

Incredibly helpful, good information to have when making decisions.

By anon85174 — On May 19, 2010

It's useful. Thank you.

By anon84991 — On May 18, 2010

great work. thanks.

By anon83594 — On May 11, 2010

I'm an ignorant in this PCs subject. Thanks because I am starting to learn!

By anon80957 — On Apr 29, 2010

Simple and to the point. Thank you.

By anon76220 — On Apr 09, 2010

Very easy. thanks.

By anon76123 — On Apr 09, 2010

Very helpful. Thanks.

By anon73988 — On Mar 30, 2010

very helpful writing indeed. thank you very much. Diganta

By anon72636 — On Mar 23, 2010

Very informative article. It explains the cache design very well. Little Jasmin97

By anon71252 — On Mar 17, 2010

Simple and straight-forward explanation. thanks to the author.

By anon67302 — On Feb 24, 2010

nice. it's easy to understand now.

By anon67084 — On Feb 23, 2010

It was excellent. I got what I need.

By anon66274 — On Feb 18, 2010

very good definition, thanks.

By anon49806 — On Oct 23, 2009

Excellent description of all levels of cache. Very clear, precise and understandable. Well done, helped me loads. Stuart

EasyTechJunkie, in your inbox

Our latest articles, guides, and more, delivered daily.

EasyTechJunkie, in your inbox

Our latest articles, guides, and more, delivered daily.