RAM DRIVE Memory-Latency or Frequency

[scaryfast]

32GB of DDR4 Quad Channel Ram is what I'll get .

16GB Ram Drive is what I'm expecting to use.

X99a Motherboard that supports overclocked memory, such as
2400 2666 3000 and 3200

DDR4 2133 is standard

1.2V is Stock
1.35 is a common overclock Voltage.

I am willing to spend a little bit more for a significant gain.

Choices include, but are not limited to

2133 - 1.2V @Timing: 15-15-15-35

2133 - 1.2V @Timing: 13-15-15-28

2400 - 1.2V @Timing: 16-16-16-39

2400 - 1.2V @Timing: 14-16-16-31

2666 - 1.2V @Timing: 16-18-18-35

2800 - 1.25V @Timing: 15-16-16-35

3000 - 1.35V @Timing: 15-16-16-35

3200 - 1.35V @Timing: 16-18-18-38

Not mentioning price because after I learn more about the principals, I'll try to determine the best cost to benefit ratio for me.

I'm not sure what the Ramdrive will even be used for. I was thinking it's possible that it will be used for file reads.

Any ideas on the "Latency - Frequency - Volts" relationships as it would concern common Ramdrive uses will be appreciated.

Thanks

 

[zir_blazer]

I'm rather interesed in this, out of curiosity. However, I'l give you a tip not related to your question: RAMDisk performance is usually highly variant depending on the tool you use to create/manage it. I recall seeing a test of several RAMDisk Software (Besides that most of the free ones have a low GB size limit, for more you have to pay), there were huge differences. The File System you format it with also adds overhead. You will probabily spend more time fine tuning the Software side of things to figure out what scales as you expect than with RAM itself.

 

[eton975]

I've gotten pretty good results with ImDisk myself.

 

[Dasa2]

timings are slightly different and im not sure how noticeable the affect would be on a ram disk but going by this 3200 16-16-16 would have better latency & rad\write speed than any of those
http://www.hardware.fr/articles/940-5/cpu-ddr4-vs-ddr3-pratique.html


and from what i have seen of prices the difference shouldnt be all that great its after 3200 that it really seems to jump

 

[john3850]

http://forums.anandtech.com/showthread.php?t=2343052&highlight=boot+from+ramdrive

post 8 and 13 have good ramdrive info.

 

[myocardia]

RAM drives are 100% identical to video cards and their bandwidth. Timings mean zero, unless you're comparing two sticks/two sets that are the same speed. Buy the fastest, i.e. highest speed in Mhz, RAM that you can afford. It will give the highest performance. If you can afford it, DDR4-3,600 @ 17-17-17 will embarrass DDR4-3,000 @ 15-15-15. THAT said, buy 32GB of DDR4-3,000, and forget about RAM drives. There are SSDs now that are nearly as fast as DDR4. Buy yourself a 400GB to 1.2TB Intel PCI-E 750 SSD. http://www.newegg.com/Product/Produ...$$$$$$$;20-167-361:$$$$$$$;20-167-294:$$$$$$$

edit: The first sentence above should really have said, "The timings of the RAM in RAM drives are identical to the horrible timings of the GDDR5 used on video cards. Timings mean close to zero, since latency falls as RAM speed rises, for all RAM of any type."

 

[zir_blazer]

RAMDisk is around 10 times faster on read/writes that a PCIe 4x 3.0 M.2 SSD. It should also have faster access latency, and higher IOPS, plus its endurance is also much higher. Problem is that it is volatile, and its practical capacity is ridiculous small - if you have a SERIOUS use, chances are that you will have to be sitting on LGA 2011-3 with 8 * 8 GB or 8 * 16 GB.

The problem is mainly the Software infrastructure that you will use for it, since the biggest con is that it is volatile. For example, since I run Windows virtualized, I could tell my Linux host to make a tmpfs RAMDisk, then assign it on boot to my Windows VM. You will not require Windows side hacks since you take care of that host side, Windows will just believe it is yet another HD. This also means that you could even reboot the Windows VM and the RAMDisk will not go boom. But you need a way to automatically backup it every now and then, which you can do after closing the Windows VM to guarantee that the RAMDisk content doesn't change when you backup it.
I think its great if you have something that isn't big in size but potentially big thrasher due to the numerous times that data on it could be hammered. Possibily a database application of some sorts?

 

[myocardia]

RAMDisk is around 10 times faster on read/writes that a PCIe 4x 3.0 M.2 SSD. It should also have faster access latency, and higher IOPS, plus its endurance is also much higher. Problem is that it is volatile, and its practical capacity is ridiculous small - if you have a SERIOUS use, chances are that you will have to be sitting on LGA 2011-3 with 8 * 8 GB or 8 * 16 GB.

I recommended skipping a RAM drive for the two underlined reasons. Since he said in the OP that he had no idea what the RAM drive would be used to do, it led me to assume that it was not aimed at being something he planned on using for business purposes, such as a database or the like. I'd personally buy a Xeon, and 128GB of registered ECC system RAM, if I were building a system to use for database type of use case.