It's a good question. More is better, as you might expect. The latest CPUs will naturally include more CPU cache memory than older generations, with potentially faster cache memory, too. One thing you can do is learn how to compare CPUs effectively.
There is a lot of information out there, and learning how to compare and contrast different CPUs can help you make the right purchasing decision. When the processor is looking for data to carry out an operation, it first tries to find it in the L1 cache. If the CPU finds it, the condition is called a cache hit.
It then proceeds to find it in L2 and then L3. When that happens, it is known as a cache miss. Now, as we know, the cache is designed to speed up the back and forth of information between the main memory and the CPU.
The time needed to access data from memory is called "latency. L1 cache memory has the lowest latency, being the fastest and closest to the core, and L3 has the highest. Memory cache latency increases when there is a cache miss as the CPU has to retrieve the data from the system memory. Latency continues to decrease as computers become faster and more efficient. In that, the speed of your system memory is also important. Cache memory design is always evolving, especially as memory gets cheaper, faster, and denser.
He enjoys copious amounts of tea, board games, and football. So, exactly how important is CPU cache, and how does it work? Now, your computer has multiple types of memory inside it. Computer memory also comes in different types, too. AMD Vs. Memory can be split into two main categories: volatile and nonvolatile.
Volatile memory loses any data as soon as the system is turned off; it requires constant power to remain viable. Most types of RAM fall into this category. Nonvolatile memory does not lose its data when the system or device is turned off. A number of types of memory fall into this category.
Sign up for our Newsletter! Mobile Newsletter banner close. Mobile Newsletter chat close. Mobile Newsletter chat dots. Mobile Newsletter chat avatar. Mobile Newsletter chat subscribe. Prev NEXT. Computer Hardware. A 1 percent reduction in hit rate has just slowed the CPU down by 10 percent. If the data has been evicted from the cache and is sitting in main memory, with an access latency of ns, the performance difference between a 95 and 97 percent hit rate could nearly double the total time needed to execute the code.
A cache is contended when two different threads are writing and overwriting data in the same memory space. It hurts the performance of both threads — each core is forced to spend time writing its own preferred data into the L1, only for the other core promptly overwrite that information. Later Ryzen CPUs do not share cache in this fashion and do not suffer from this problem. This graph shows how the hit rate of the Opteron an original Bulldozer processor dropped off when both cores were active, in at least some tests.
Zen 2 does not have these kinds of weaknesses today, and the overall cache and memory performance of Zen and Zen 2 is much better than the older Piledriver architecture. These tiny cache pools operate under the same general principles as L1 and L2, but represent an even-smaller pool of memory that the CPU can access at even lower latencies than L1.
Often companies will adjust these capabilities against each other. These kinds of trade-offs are common in CPU designs. Recently, IBM debuted its Telum microprocessor with an interesting and unusual cache structure. IBM can even share this capability across multi-chip systems, creating a virtual L4 with a total of MB of data storage. Cache may be 40 years old at this point, but manufacturers and designers are still finding ways to improve it and expand its utility.
Cache structure and design are still being fine-tuned as researchers look for ways to squeeze higher performance out of smaller caches. Presumably, the benefits of a large L4 cache do not yet outweigh the costs for most use-cases. Regardless, cache design, power consumption, and performance will be critical to the performance of future processors, and substantive improvements to current designs could boost the status of whichever company can implement them.
This site may earn affiliate commissions from the links on this page. Terms of use. Image by Anandtech. This newsletter may contain advertising, deals, or affiliate links.
0コメント