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whether we're talking dollars in your bank account items on a seafood buffet

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or dates you've got lined up on tinder more is generally considered to be

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better a sentiment that also seems to hold true with the number of cores in

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your computer CPU at least if you buy into the marketing hold on even though

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having many cores definitely gives you a boost in multi-threaded applications

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like rendering 3d animations there are

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actually situations where more cores gives no benefit whatsoever or can even

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actually hurt your system's performance

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but how could this be well to start off with the more cores

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you pack onto a CPU the more power they need and the more heat they generate and

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remember that because CPU cores are crammed into a relatively small space

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manufacturers end up working against some serious limits when it comes to

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thermal design power or TDP this means that to prevent the CPU from

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drawing too much power and producing too much heat the individual cores have

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traditionally run their clock frequencies lower to improve efficiency

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and even if the advertised boost clock for a CPU with lots and lots of course

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can appear to be high it's often the case that they cannot

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maintain these clocks for long periods of time or that they only do it when

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you're running very light applications so if you're using your computer mostly

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for applications where single threaded performance matters more such as games

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that super expensive 18 core CPU might

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actually yield you a worse experience than something cheaper

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and if you go with a really high core count CPU there's another wrinkle with

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how processors with that many cores access the system memory you see in some

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cases these larger cpus need to have their core split into two groups or

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nodes of course with each group getting its own memory controller and segment of

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the physical memory in a scheme called non-uniform memory access or pneuma

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this is generally quicker than the opposite solution called uniform memory

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access or yuma where all the cores share

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one big pool of memory but here's the thing a CPU that uses pneuma which is

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better for latency sensitive applications can often struggle when

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running a single program that uses tons of threads

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because of the different memory access times between the nodes and the fact

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that each node would have to wait on the other one to finish working on the same

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data highly multi-threaded programs like these often don't want to cross nodes

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even if it would mean being able to take advantage of the entire CPU

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so back to yuma then right no

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because one controller manages all the memory accesses to give every program

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equal time rather than allowing access to the memory more directly as in numa

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yuma has a built-in performance penalty

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that increases the more nodes your system has to manage

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so using a CPU with separate groups of cores means you're going to be subjected

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to one of these drawbacks and you're going to take a performance hit either

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way and these are problems that you simply don't run into on smaller chips

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with fewer cores because you're not dealing with multiple nodes

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but getting away from memory access sometimes the cores themselves are even

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designed in a way that bottlenecks them the more of them you slap onto a chip do

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you remember how before ryzen AMD processors seemed to be significantly

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slower than Intel despite having more cores

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well a big reason for this was that those old bulldozer fx processors didn't

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use full cores instead an fx CPU advertised as having a

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cores would in reality have eight integer units but only four floating

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point units that were shared between the eight cores so if you don't know what a

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floating point unit is you can learn more about that right up here but the point is you could think of these cpus

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as having four half cores that were missing which

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severely hampered their single threaded performance in some key applications

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now this design allowed AMD processors to handle more threads for a cheaper

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price but it also meant that their real-world performance legged way behind

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Intel and the only way AMD could try and compensate was to increase clock speeds

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which increased heat output and contributed to AMD's reputation for hot

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running cpus for many years so what's our bottom line then although both AMD

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and Intel are using much wiser strategies for their many core cpus and

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clever boosting techniques to give them similar single threaded performance to

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their less costly brethren if the best sales pitch for a super

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premium product is that it doesn't suffer a performance penalty in the

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applications that you use well you'd better make sure you've got a use

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case for it before spending your hard earned cash and no playing fortnight and

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watching techwiki definitely don't count

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and neither does using brilliant because you can kind of do it anywhere effective

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learning guys is active not passive so learning from lectures and videos is

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just not as fast as diving in and doing things yourself and brilliant is a

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problem-solving based website and app with a hands-on approach with over 60

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interactive courses in math science and computer science brilliant lets you

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master concepts by solving fun challenging problems for yourself rather

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than by watching someone else do it and this is really useful if you're in a

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stem course their courses have storytelling code writing interactive

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challenges and problems to solve and you can check out great courses like the one

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on search engines so you can learn how it is that google answers a question in

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a fraction of a second even though there are so many billions of sites to search

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through so check it out now because the first 200 of you to head to brilliant.org

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techwiki we're going to have that linked below are going to get 20 off their

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annual premium subscription so thanks for watching guys like dislike

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check out our other videos and don't forget to subscribe

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