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> got 3200MHz RAM also, which booted into 2333MHz as well (will need to wait for motherboard update to get full speed I guess) The highest official DDR4 freque

> got 3200MHz RAM also, which booted into 2333MHz as well (will need to wait for motherboard update to get full speed I guess) The highest official DDR4 frequency is 2400MHz. Anything beyond that is technically overclocking. Testing has shown that there is very little performance benefit above 2666MHz. [0] The long and short is that manufacturers are happy to sell you 3200MHz RAM, but you're paying for speed you'll likely never use: your CPU memory controller needs to be stable at those overclocked speeds, and the performance gains are minimal. [0] https://www.youtube.com/watch?v=D_Yt4vSZKVk https://www.youtube.com/watch?v=D_Yt4vSZKVk

floatboth 9y ago
Of course RAM overclocking only really matters for overclockers' benchmarks ( e.g. Super Pi: 6m37s @ 2133 MHz, 6m6s @ 4000 MHz https://youtu.be/NiZXmijRRjw https://youtu.be/NiZXmijRRjw ) However on Ryzen, RAM frequency directly determines the frequency of the bridge between the two 4-core complexes the CPU is made of! This matters a lot.
onli 9y ago
While it may be technically overclocking, the default ram clock of Ryzen boards is DDR4-2666. If you look at the right benchmarks you will see that faster ram can bring enormous performance benefits, even in games, which is an area where the contrary was claimed in the last few years. Some examples are https://www.youtube.com/watch?v=G5ejBlynOV8 https://www.youtube.com/watch?v=G5ejBlynOV8 and https://www.reddit.com/r/buildapc/comments/5agh8f/skylake_cpu_and_ram_gaming_impact_benchmarked/ https://www.reddit.com/r/buildapc/comments/5agh8f/skylake_cp.... That's for Intel, but the same is true for AMD and Ryzen.
- kogepathic 9y ago
  > you will see that faster ram can bring enormous performance benefits Okay, so looking at the spreadsheet of results from the Reddit thread [0]: - Overclocking the RAM from 2133MHz to 3000MHz resulted on average an 8% increase in FPS. This is a 40% higher frequency netting on average 8% more performance - They only tested two speeds: 2133MHz and 3000MHz I would imagine that the difference between 2400MHz (officially the top speed of DDR4) and 3000MHz would be even less than the 8% they found. Let's assume, based on no evidence whatsoever, that the performance gains are linear. For 40% increase in RAM clock, you get 8% performance gain. So from: - 2400MHz->3000MHz: 5% increase in performance - 2666MHz->3000MHz: 2.5% increase in performance You also have to account for the fact that: - Higher speed RAM costs more - Overclocking will consume more power and generate more heat Based on the above, where the average benefit from a 40% RAM overclock was a mere 8% performance gain, I'm just not seeing how "enormous" the performance benefits are. [0] https://docs.google.com/spreadsheets/d/1LKmt9FDEjFXeu3USK1bzjzRidhg3frgwWx7mPUlOWEc/edit#gid=1267098471 https://docs.google.com/spreadsheets/d/1LKmt9FDEjFXeu3USK1bz...
  - onli 9y ago
    8% are huge for something that was said to be of no relevance at all in that specific workload. And it is 8% for a small price difference. Ram prices are in flux currently, but right now I see 16GB DDR4-2400 for 119€ and 16GB DDR4-3000 for 139€. Some time ago the price was almost identical. Also, please watch the video as well. The practical effect of having faster ram on frametimes is immense and sometimes a lot bigger than what you'd expect. Moving from just barely reaching 60 FPS in the Crysis train sequence to comfortable 80, with an i3, is very nice. There is also the Ryse sequence (~ at minute 7) where performance of the i3 doubles, just because of the faster ram.
deleted 9y ago
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thomastjeffery 9y ago
The highest official DDR3 frequency is 1600Mhz. My 8320e board is happily chugging along at 2400Mhz. That's 50% faster. In fact, my motherboard is advertised at a 2133Mhz max, and so is my memory. "Official" frequencies are a very poor metric. You might as well run your memory as fast as you can, so long as it's still stable. If you are concerned about stability, just run a few iterations of memtest86.

floatboth 9y ago

Of course RAM overclocking only really matters for overclockers' benchmarks ( e.g. Super Pi: 6m37s @ 2133 MHz, 6m6s @ 4000 MHz https://youtu.be/NiZXmijRRjw https://youtu.be/NiZXmijRRjw ) However on Ryzen, RAM frequency directly determines the frequency of the bridge between the two 4-core complexes the CPU is made of! This matters a lot.

onli 9y ago

While it may be technically overclocking, the default ram clock of Ryzen boards is DDR4-2666. If you look at the right benchmarks you will see that faster ram can bring enormous performance benefits, even in games, which is an area where the contrary was claimed in the last few years. Some examples are https://www.youtube.com/watch?v=G5ejBlynOV8 https://www.youtube.com/watch?v=G5ejBlynOV8 and https://www.reddit.com/r/buildapc/comments/5agh8f/skylake_cpu_and_ram_gaming_impact_benchmarked/ https://www.reddit.com/r/buildapc/comments/5agh8f/skylake_cp.... That's for Intel, but the same is true for AMD and Ryzen.

kogepathic 9y ago
> you will see that faster ram can bring enormous performance benefits Okay, so looking at the spreadsheet of results from the Reddit thread [0]: - Overclocking the RAM from 2133MHz to 3000MHz resulted on average an 8% increase in FPS. This is a 40% higher frequency netting on average 8% more performance - They only tested two speeds: 2133MHz and 3000MHz I would imagine that the difference between 2400MHz (officially the top speed of DDR4) and 3000MHz would be even less than the 8% they found. Let's assume, based on no evidence whatsoever, that the performance gains are linear. For 40% increase in RAM clock, you get 8% performance gain. So from: - 2400MHz->3000MHz: 5% increase in performance - 2666MHz->3000MHz: 2.5% increase in performance You also have to account for the fact that: - Higher speed RAM costs more - Overclocking will consume more power and generate more heat Based on the above, where the average benefit from a 40% RAM overclock was a mere 8% performance gain, I'm just not seeing how "enormous" the performance benefits are. [0] https://docs.google.com/spreadsheets/d/1LKmt9FDEjFXeu3USK1bzjzRidhg3frgwWx7mPUlOWEc/edit#gid=1267098471 https://docs.google.com/spreadsheets/d/1LKmt9FDEjFXeu3USK1bz...
- onli 9y ago
  8% are huge for something that was said to be of no relevance at all in that specific workload. And it is 8% for a small price difference. Ram prices are in flux currently, but right now I see 16GB DDR4-2400 for 119€ and 16GB DDR4-3000 for 139€. Some time ago the price was almost identical. Also, please watch the video as well. The practical effect of having faster ram on frametimes is immense and sometimes a lot bigger than what you'd expect. Moving from just barely reaching 60 FPS in the Crysis train sequence to comfortable 80, with an i3, is very nice. There is also the Ryse sequence (~ at minute 7) where performance of the i3 doubles, just because of the faster ram.

deleted 9y ago

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thomastjeffery 9y ago

The highest official DDR3 frequency is 1600Mhz. My 8320e board is happily chugging along at 2400Mhz. That's 50% faster. In fact, my motherboard is advertised at a 2133Mhz max, and so is my memory. "Official" frequencies are a very poor metric. You might as well run your memory as fast as you can, so long as it's still stable. If you are concerned about stability, just run a few iterations of memtest86.