What do all these numbers mean?

[itsTrickAF]

Hey guys,

 

I'm looking at upgrading the RAM in my laptop but I have no idea what the different numbers mean. Could someone help me out? For the exact same price, I'm seeing:

• DDR3 1866 PC3L 14900 CAS Latency 11
• DDR3 1600 PC3L 12800 CAS Latency 9

What do all these differences mean? Which one's better?

[suchamoneypit]

One set is DDR3 RAM clocked at 1866mhz, with a latency of 11.

 

Another set is DDR3 RAM clocked at 1600mhz, with a latency of 9.

 

One is slightly faster, with more latency, and one is slightly slower, but with less latency. If it were me, I'd take the 1866mhz memory as its not that high latency - I'd rather have higher clockrate. In reality they will perform extremely similar.

[Streetguru]

5 minutes ago, itsTrickAF said:

 

Are you just trying to double your RAM or something? Because faster RAM is unlikely to be worth it or make any major difference.

 

Those are just the speeds/latency, high speed with high latency is comparable to a lower speed with lower latency in terms of performance.

 

Really doesn't matter either way, buy whatever is cheaper unless the slightly faster stuff is the same price.

[itsTrickAF]

1 minute ago, Streetguru said:

Are you just trying to double your RAM or something? Because faster RAM is unlikely to be worth it or make any major difference.

 

Those are just the speeds/latency, high speed with high latency is comparable to a lower speed with lower latency in terms of performance.

 

Really doesn't matter either way, buy whatever is cheaper unless the slightly faster stuff is the same price.

More than double, actually. There's currently only 4GB of DDR3 1333mhz in there right now, so I'm going to bump it up to 16GB. Both of these kits are listed at $95 on newegg but other than the frequency I have no clue what the other numbers meant.

[itsTrickAF]

@Streetguru @suchamoneypit

 

This laptop is ~8 years old now. I'm not entirely positive if it will even support the higher speed RAM. If their performance will be roughly identical, should I take the one with lower speed as well as lower latency just in case the one with higher speed down-clocks anyways so that I don't get stuck with higher latency?

[schwellmo92]

It's unlikely your laptop will run them at that speed, check what your laptop specification is and that's the fastest they'll run. If the laptop is 8 years old it's probably not worth the $100 investment tbh.

[Streetguru]

17 minutes ago, itsTrickAF said:

More than double, actually. There's currently only 4GB of DDR3 1333mhz in there right now, so I'm going to bump it up to 16GB. Both of these kits are listed at $95 on newegg but other than the frequency I have no clue what the other numbers meant.

Just buy your laptop RAM off of ebay, should be way cheaper, RAM is basically indestructible anyways.

[itsTrickAF]

15 minutes ago, schwellmo92 said:

It's unlikely your laptop will run them at that speed, check what your laptop specification is and that's the fastest they'll run. If the laptop is 8 years old it's probably not worth the $100 investment tbh.

It's still a solid laptop though.

• i7-2670QM that runs at 3.1GHz, full 4-core 8-thread processor
• 17.3in 1600x900p display
• Blu-ray drive
• Fingerprint Reader
• 3 Front-facing speakers and a subwoofer
• 1TB Hard Drive
• 250GB Samsung 860 EVO ($56) that I just threw in it so it's pretty snappy

I don't see any reason to get a new laptop when it just needs a RAM upgrade. ~$150 for the SSD and RAM is worth it to revive a $900 laptop.

[AskTJ]

That laptop isn't worth $900 though. Used kits on eBay are the way to go as said by @Streetguru.

[EG!]

Your title instantly triggerd this in my head.

 

[Streetguru]

33 minutes ago, itsTrickAF said:

 

What are you doing on the laptop that requires more RAM though?

[jj9987]

Since no one really gave an in-depth explanation of numbers, I'll do it. Real-life differences are not really noticeable, unless you are using Ryzen platform, which can take advantage of higher memory speeds.

1 hour ago, itsTrickAF said:

• DDR3 1866 PC3L 14900 CAS Latency 11
• DDR3 1600 PC3L 12800 CAS Latency 9

DDR3 - Double Data Rate, 3rd gen of Dynamic Random-Access Memory (DRAM).

1866 - frequency of memory it is working at.

PC3L - PC3 indicated that it is DDR3, L stands for Low-Power, meaning it can run at 1.35V as well in addition to DDR3 standard voltage of 1.5V.

14900 - module name, matches with memory frequency (DDR3-1866 = PC3-14900)

CAS Latency - memory latency, how many nanoseconds it takes to access to read or write to memory. CAS latency is calculated, kind of an average of latency for many different operations.

 

In general, the fastest memory has the highest frequency and lowest latency.

Spoiler

 

[schwellmo92]

3 hours ago, itsTrickAF said:

It's still a solid laptop though.

• i7-2670QM that runs at 3.1GHz, full 4-core 8-thread processor
• 17.3in 1600x900p display
• Blu-ray drive
• Fingerprint Reader
• 3 Front-facing speakers and a subwoofer
• 1TB Hard Drive
• 250GB Samsung 860 EVO ($56) that I just threw in it so it's pretty snappy

I don't see any reason to get a new laptop when it just needs a RAM upgrade. ~$150 for the SSD and RAM is worth it to revive a $900 laptop.

That’s not to bad I guess, your maximum supported DDR3 frequency is 1333MHz.

[itsTrickAF]

11 hours ago, schwellmo92 said:

That’s not to bad I guess, your maximum supported DDR3 frequency is 1333MHz.

How did you figure out the max supported frequency?

[schwellmo92]

8 hours ago, itsTrickAF said:

How did you figure out the max supported frequency?

The specs for the CPU on the Intel specification page tell you.

 

https://ark.intel.com/products/53469/Intel-Core-i7-2670QM-Processor-6M-Cache-up-to-3-10-GHz- -> Ctrl+F "Memory Types"

[ProximaOfZeal]

Usually RAM will remain stable if you tweak latency a little bit (I'm running two different 1600 CL11 sticks together at CL9 with no problems), but I'm not sure if laptops allow such tweaks (I believe big OEM brands like HP or Dell don't).

 

But I agree with @Streetguru, I've been pretty much buying only used RAM for my laptops and I never had any problems, just make sure that the seller has tested it.

Furthermore, in my desktop I'm using DDR3 ram that I found in electronic scrap, it has been lying in the bottom of a box full of old liquidated office trash, crushed by it and all, and it still ended up working perfectly.