General Discussions

[knight_h]

Hi everyone ! 

Yet again another point that caught my eye with Ryzen 4000 series. 

I found various ultrabooks coming out with Ryzen 7 4700U. However when comparing the performances of this processors with other 4000 series CPUs I got a bit confused ! 

The 4700U looks very similar to 4800U without the SMT(simultaneous multithreading) and with a slightly less performant GPU. The 4700U has 8 cores / 8 threads while 4800U offers 8 cores / 16 threads. At this point I can understand that 4800U should perform much better at multi-core computing as it can be seen on benchmarks (cpubenchmark.net / cpu-monkey).

Even if at this point I wonder if it is really justified for someone to go for 4700U while the price difference with 4800U is not that big, things become really weird when I compared Ryzen 7 4700U with Ryzen 5 4600U. The Ryzen 5 4600U has 6 cores/12 threads and it gets 3% less performance at single-threading but performs better than Ryzen 7 4700U at multi-core processing by 7%  while it is cheaper than 4700U !

     (source : cpubenchmark.net)

So I'm really wondering why did AMD commercialise the 4700 ?  Is there any technical reason behind this or it is only a marketing strategy ? 

Thank you in advance ! 

[black_zion]

Product segmentation. The 4800U has an additional GPU core as well as SMT while the 4700U has one fewer GPU core and lacks SMT. This makes the 4700U a lower cost option for laptop manufacturers, which they can use in lower priced models, and use it as a base in order to charge more for the 4800U upgrade.

[knight_h]

Thank you very much for your helpful answer. 

Indeed the 4800U seems more powerful than 4700U, but how the similar performances of 4700U compared to Ryzen 5 4600U can be justified ? 

Alternatively one can doubt how accurate benchmarks based on Cinebench or Geekbench are. For example on userbenchmark.com I found completely different benchmarks for the 3 mentionned CPUs and this time the 4700U is placed juste near the 4800U (yet their benchmark method is at some points very contested). 

[black_zion]

Because the 4600U has 2 fewer CPU cores and 1 fewer GPU core?

[knight_h]

Hi black_zion‌ !

Thanks again for your reply and sorry to be late. 

Indeed 4700U has better graphics, but in terms of CPU even if 4600U has 2 fewer cores, as it has multi-threading it comes with 12 threads while 4700U has only 8 threads, thus the better multi-core benchmarks for 4600U.

I contacted Lenovo and they don't know when the 4800U will be available again on their products but I hope that AMD can restock them soon... 

[black_zion]

You can't always say that a CPU with fewer physical cores but more logical processors than a CPU with more physical cores but fewer logical processors will always be faster, as the benefits of SMT vary.

[knight_h]

It seems legit. thank you very much for your help