Question Comparing RAM; what 32GB set is right for me?

[HerbertSherbet]

This is driving me bonkers. My build is almost complete but I don't want to wildly guess what DIMMs to buy. I don't understand my options well enough for me to make a decision. Teach a man to fish and he can pick out his own RAM.

How much improvement is there between timings and latency? I understand that there are diminishing returns but what sorts of meaningful differences might I see?

How do I compare brands? How do I keep a watchful eye out for bad quality parts? How much difference is there between a $200 and $125 kit?

What's the difference between 2x16GB and 4x16GB for a dual channel motherboard? I want to take the risk of going 2x16GB and adding RAM later but how much am I sacrificing?

Those are my questions. Let's get specific. Looking for starting points on PCPartPicker I found two kits of 2x16 GB DDR4-3200 Memory that cost $125 and $200 respectively. Same CAS, same voltage, but slightly different timings and with one having RGB. "16-18-18-38" versus "16-18-18-36" What warrants the $75 jump?
https://pcpartpicker.com/product/f7KcCJ
https://pcpartpicker.com/product/yMJtt6

I would love it if you could talk specifics between specific items or, heck, even give me a suggestion.

My build primarily focused as a tool for video editing, running code, and multi-tasking documents/PowerPoints. I'm already content with the videogaming capabilities of the system but I don't want to bottleneck myself either. I intend to do no overclocking what-so-ever. I will be running everything at 1080p and need this machine to function correctly for at least 5 years.
Here are my specs:

CPU: Intel Core i7-9700K Coffee Lake 8-Core 3.6 GHz (4.9 GHz Turbo) LGA 1151 (300 Series) 95W BX80684I79700K Desktop Processor Intel UHD Graphics 630
https://www.newegg.com/core-i7-9th-gen-intel-core-i7-9700k/p/N82E16819117958

CPU Cooler: Noctua NH-D15S 140mm SSO2 D-Type Premium CPU Cooler, NF-A15 PWM Fans
https://www.newegg.com/p/N82E16835608072

Motherboard: GIGABYTE Z390 AORUS PRO LGA 1151 (300 Series) Intel Z390 HDMI SATA 6Gb/s USB 3.1 ATX Intel Motherboard
https://www.newegg.com/p/N82E16813145098
https://www.gigabyte.com/Motherboard/Z390-AORUS-PRO-rev-10/support#support-manual

GPU: SAPPHIRE PULSE Radeon RX 5700 DirectX 12 100417P8GL 8GB 256-Bit GDDR6 PCI Express 4.0 x16 ATX Video Card
https://www.newegg.com/sapphire-radeon-rx-5700-100417p8gl/p/N82E16814202350

PSU: Will be at minimum 30% higher than 97 watts above the final wattage rating of my parts with at least an 80% rating from a brand I can trust.

Memory: 2x16GB to be ran as Dual Channel. I can't imagine needing more RAM than 32GB but I want to stay flexible enough to upgrade.

Storage: 1TB of SSD storage as a boot drive with separate HDD storage added after the system is built.

 

[bmockeg]

PCPartPicker Part List

Memory: G.Skill Trident Z RGB 32 GB (2 x 16 GB) DDR4-3600 Memory ($164.99 @ Newegg)
Total: $164.99
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2019-11-19 19:25 EST-0500

 

[HerbertSherbet]

PCPartPicker Part List

Memory: G.Skill Trident Z RGB 32 GB (2 x 16 GB) DDR4-3600 Memory ($164.99 @ Newegg)
Total: $164.99
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2019-11-19 19:25 EST-0500

Okay! So...

I see the timings are 16-19-19-39 but with +400 MHz. (Also with pointless RGB.)
2x32GB DDR4-3200 16-18-18-38 =$125
2x32GB DDR4-3200 16-18-18-36 =$200
2x32GB DDR4-3600 16-19-19-39 =$165

+/-0, +1, +1 +1 with latency of 8.8 repeating instead of 10
They all have a heat spreader.

It's been 35 minutes but I don't know what this MEANS! The PC-rating speeds don't help because it's redundant when not cross-comparing with DDR3 or lower. I have done so much reading and video watching but I still don't understand this because the vast majority of what I find is restating all the surface level definitions. I look at benchmarks but it's like taking a magnifying glass up against a wall.

 

[bmockeg]

https://notkyon.moe/ram-latency.htm

Higher speed and lower latency is what you want. Intel has a performance gain up to 3600mhz and then the price to performance ratio drops off. You can get timings of 16-16-16-36 but they are a lot more expensive. If you want DDR 3200 then you want CAS 14. If I was building a computer today it would be with the RAM I linked for you above.

 

[HerbertSherbet]

https://notkyon.moe/ram-latency.htm

Higher speed and lower latency is what you want. Intel has a performance gain up to 3600mhz and then the price to performance ratio drops off. You can get timings of 16-16-16-36 but they are a lot more expensive. If you want DDR 3200 then you want CAS 14. If I was building a computer today it would be with the RAM I linked for you above.

I appreciate that. It does help to view that kit as a ceiling for reference. I saw that same set before in an article and I've seen it since in a youtube video, so I certainly understand how it would be your favored choice.


On a side note I think I confused myself at some point. I thought 2x32GB meant two sticks of 16GB each, not two sticks of 32GB each. I feel really silly now.

 

[bmockeg]

All good, I figured what you meant.

 

[HerbertSherbet]

That item you mentioned sold out. I can tell that I don't understand these comparisons. I understand the general CAS latency, but this number doesn't take into account the other three.

https://www.newegg.com/g-skill-32gb-288-pin-ddr4-sdram/p/N82E16820232906
DDR4-3600 (PC4 28800)
16-19-19-39
1.35V
Calculated nanoseconds: 8.88

https://www.newegg.com/g-skill-32gb-288-pin-ddr4-sdram/p/N82E16820232920
DDR4-3600 (PC4 28800)
18-22-22-42
1.35V
Calculated nanoseconds: 10

tRCD: RAS to CAS Delay. The time it takes between the activation of the line (RAS) and the column (CAS) where the data are stored in the matrix.
tRP: RAS Precharge. The time it takes between disabling the access to a line of data and the beginning of the access to another line of data.
tRAS: Active to Precharge Delay. How long the memory has to wait until the next access to the memory can be initiated.

Am I misunderstanding? Is the CAS Latency the sum of these numbers? If not, how do I take the other three timing sets into consideration?

 

[bmockeg]

That item you mentioned sold out. I can tell that I don't understand these comparisons. I understand the general CAS latency, but this number doesn't take into account the other three.

https://www.newegg.com/g-skill-32gb-288-pin-ddr4-sdram/p/N82E16820232906
DDR4-3600 (PC4 28800)
16-19-19-39
1.35V
Calculated nanoseconds: 8.88

https://www.newegg.com/g-skill-32gb-288-pin-ddr4-sdram/p/N82E16820232920
DDR4-3600 (PC4 28800)
18-22-22-42
1.35V
Calculated nanoseconds: 10




Am I misunderstanding? Is the CAS Latency the sum of these numbers? If not, how do I take the other three timing sets into consideration?

They all add to latency but the first number is most important. You want them to be as low as possible within your budget.

 

[bmockeg]

PCPartPicker Part List

Memory: G.Skill Trident Z Neo 32 GB (2 x 16 GB) DDR4-3600 Memory ($169.99 @ Amazon)
Total: $169.99
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2019-11-22 15:28 EST-0500

 

[HerbertSherbet]

Thank you for your continued generosity with your time. Sorry for sounding so panicked. I'm trying to buy the parts during Black Friday and Cyber Monday so I'm rushing around trying to square things away.

 

[bmockeg]

Thank you for your continued generosity with your time. Sorry for sounding so panicked. I'm trying to buy the parts during Black Friday and Cyber Monday so I'm rushing around trying to square things away.

No worries