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eDRAM vs L3 Cache

IAria2
Beginner
5,487 Views

What is the difference or equivalence between eDRAM 128MB and L3 cache 8MB?

 

Which is better and why?

 

Which is older?

 

Which is more popular?

 

Why technology is not driven with the best?

 

Why sometimes they consider one or the otther?

 

Thanks.

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IAria2
Beginner
5,364 Views

If I give you an example like having two same specs like 32 ram, 4.0Ghz to 5.0Ghz Turbo Boost and but one have L3 cache 16MB other have 128MB eDRAM, in terms of miliseconds whichone will be snappier? or let reduce the example to 1 of ram & 1Ghz but keeping L3 16MB vs 128MB eDRAM.

 

1) which will open programs faster?

2) which will be more laggy?

3) which will consume more energy?

4) which will read data faster?

5) which will write data faster?

 

I want PhD reply but with yours will be helpful too.

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n_scott_pearson
Super User
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eDRAM (Embedded DRAM) is memory built into the processor that is specifically used to support the operation of the Intel Iris Plus graphics engine. The L3 Cache is a write-through cache that supports the execution of the processor cores. There is a detailed explanation of processor caches in Wikipedia: https://en.wikipedia.org/wiki/CPU_cache. There is no real comparison that would allow you to say that one is better than the other. They do different things, in different ways, on behalf of different parts of the processor.

 

L3 caches have been around for a long, long time. In fact, being the old f@rt that I am, I remember working on systems whose L3 cache was implemented on the motherboard, not in the processor. eDRAM, on the other hand, is a fairly new technology for the processor. It is not a popularity contest, but I would certainly say that having eDRAM in the processor has allowed the Iris Plus Graphics engine to reach higher performance levels than the standard Intel HD/UHD Graphics engines.

 

I am not sure what you last two questions are asking for. In making any decision, implementation and support costs, technology readiness, risk, impact, etc. all have to be factored into the decision-making process. It is often a delicate balancing act. We in the industry often refer to it as being on the bleeding edge. See this article: https://en.wikipedia.org/wiki/Bleeding_edge_technology.

 

...S

 

 

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Shashank_Yadav
Beginner
4,968 Views

Thank you for the answer. I have the same question. In the image you can see that there are 2 macbook categories. On one one its written eDram & on the other it's written L3 cache. 

A simple question: Which one is better ?

 Screenshot 2020-08-10 at 3.21.24 PM.png

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n_scott_pearson
Super User
4,936 Views

These processors all have sufficient - and typically the same size - L3 caches. If the EDRAM cache is present, it is there in addition to the L3 cache, in order to help better handle graphics accesses.

Which you purchase is up to you. It depends upon what you plan to do with it. If you are going to be gaming or otherwise generating intense graphics loads, the 8 Series processor with it's EDRAM and Iris Plus graphics will probably do you better. If you are doing more-general computing and don't have intense graphics load requirement, the slightly better Core performance and the higher core count of the 10th gen processors will be better.

Any analysis beyond this level, you are on your own.

...S

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IAria2
Beginner
5,365 Views

If I give you an example like having two same specs like 32 ram, 4.0Ghz to 5.0Ghz Turbo Boost and but one have L3 cache 16MB other have 128MB eDRAM, in terms of miliseconds whichone will be snappier? or let reduce the example to 1 of ram & 1Ghz but keeping L3 16MB vs 128MB eDRAM.

 

1) which will open programs faster?

2) which will be more laggy?

3) which will consume more energy?

4) which will read data faster?

5) which will write data faster?

 

I want PhD reply but with yours will be helpful too.

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n_scott_pearson
Super User
5,364 Views

As I said, you simply cannot compare them like this. The L3 cache is used to buffer memory R/W operations for the processor Cores. The 128MB eDRAM cache, on the other hand, is used to buffer operations for the Iris Plus Graphics engine.

...S

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