4+4 RAM or 4+8 RAM configuration on laptop: Lenovo g580

[Saksham Prakash]

My laptop specs-
i5 3rd Gen
4GB RAM Hynix HMT351S6CFR8C-PB 1600mhz
Intel HD 4000
750 GB HDD

My laptop has two RAM slots.

Questions:
1. Should I get another 4GB stick (4+4 config) or an 8GB stick (4+8 config)?
2. Should I get the same RAM stick (Hynix HMT351S6CFR8C-PB 4GB) available online or go to the local market to get it installed and checked for compatibility there only (I'm not getting the exact same Hynix stick in the local market)?
3. What are the other specs of the new memory to be taken care of before purchasing, for maximum compatibility with the old memory, apart from the 1600mhz frequency?

Note:
I have faced RAM incompatibility issues before. I have also faced issues with amazon sellers sending fake products to me. All this makes me want to go to the local market and get the RAM upgraded even if I don't get the exact same stick as already installed.

 

[jasonkaler]

I personally would get the 8GB, even if it is slightly different.
RAM compatibility is sometimes just hit and miss, but if they're different sizes, you'll probably have more luck as the motherboard won't even attempt to run them in dual channel.
As for frequency, using the exact same frequency is not really that important. i personally would go for a higher frequency as then it will step down to the correct frequency, where as the exact same frequency may have timing issues.

 

[Saksham Prakash]

I personally would get the 8GB, even if it is slightly different.
RAM compatibility is sometimes just hit and miss, but if they're different sizes, you'll probably have more luck as the motherboard won't even attempt to run them in dual channel.
As for frequency, using the exact same frequency is not really that important. i personally would go for a higher frequency as then it will step down to the correct frequency, where as the exact same frequency may have timing issues.

Does having more memory (4+8) single channel outweigh the benefits of running dual channel (4+4)?

 

[jasonkaler]

Does having more memory (4+8) single channel outweigh the benefits of running dual channel (4+4)?

I've seen very little benefit from dual channel. Most games and apps only show a 1% improvement in benchmarks.
Having the extra 4GB of RAM will come in handy, especially in the long term.