8GB RAM Advice for X220

Hi
According to Crucial, the recommended 8GB RAM for the X220 is:

8GB PC3-10600 DDR3 SDRAM 1333MHz SODIMM (2 DIMM)

But the following is also compatible...would this be significantly better? (not much difference in cost)

8GB PC3-12800 DDR3 SDRAM 1600MHz SODIMM (2 DIMM)

Cheers

 

Not significantly better. Slightly better in benchmarks, but overall performance increases will be negligible.

 

Unless you've got a specific need, 8GB is probably a waste too, my opinion of course.

 

Well, I think one of the biggest benefits of 8GB of RAM is that you're able to reduce you page file/swap size to essentially nill.

With SSD's though, it's a bit of a double edge sword as by eliminating the page file/swap you eliminate thrashing of your precious SSD, but by increasing the RAM size, you also increasing the amount that needs to be written to the SSD in the event that you choose to hibernate.

With an SSD, ideally, it seems that you'd want your machine to only sleep.

I'd be very curious to know how many watts a T420s/X220 pull when the machine is in sleep mode.

 

According to my power consumption meter, my sleeping X220 alternates between 0 watts and 1.7 watts (spending more seconds on the former).

By comparison, when idling and connected to an external display, it uses about 11.5 watts . Not connected, about 13 watts at medium brightness.

So with a mSATA/ HDD combo and 8GB standard ram, just leave the file/swap 'as is'?

Are you saying a SSD prefers sleeping to being turned off?

 

The only time you would need a page/swap file is if you had more programs running that your memory could handle.

The benefit of 8GB of ram is that even with a few programs open, you would rarely ever go beyond your physical memory limit, thus you'd never use/need a page file.

With regards to the SSD and sleep, I can't think of any reason why the SSD would need to be powered on when the machine is in sleep mode. The entire contents of the Windows session resides in memory, so the SSD does not come into play.

I guess the only thing of concern might be if you frequently put the SSD to sleep over a short period of time. I read somewhere that frequent charges/discharges of an SSD's flash cells can degrade them over time... This is by no means fact as I've read so many articles now while researching my M4 purchase that I'll have to try and dig this one up.

 

8GB is the best option for X220, because 4GB may not be plenty for 64-bit OS, while 6GB is asymmetric dual channel which cripples performance. (Note: I hate virtual memory, even on the best SSD.)

The Kingston HyperX 1866MHz or something, is said to be great. However I still prefer 8GB customized at Lenovo, because it saves me a day to run memtest86+.

 

I dunno about the 1866MHz, but there doesn't seem to be much real world difference between the 1333Mhz and 1600Mhz kits.

Not only is the 1866Mhz priced out of most peoples reach, they also have CAS 11 latency.

 

The performance hit resulting from 6GB is actually quite small. I've benchmarked 4GB, 6GB and 8GB combinations. I'm using 6GB because occasionally 4GB is not enough and 8GB results in noticeably longer hibernation and resume times.

The CAS 11 is at 1866 MHz when the clock cycles are shorter than at 1600MHz (which, in turn, has shorter clock cycles than 1333MHz. You need to compare the physical time.

John

 

I would just add that putting it into deeper sleep (C4) makes no difference to the above figures (ie it still alternates between 0 and 1.7). I thought that deeper sleep was meant to lower consumption?

Anyhow, I have it enabled unplugged and disabled plugged.

 

Yep, you're right. Physical response time is really the only way to compare memory.

As per wiki, physical latency can be calculated as (CAS / Frequency (in Mhz) x 1000 = Xns

So, for a typical 8GB kit of 1333Mhz RAM with CAS of 9, you looking at 13.5ns of latency... (8/667) x 1000 = 13.5ns

For a typical 8GB kit of 1866Mhz RAM with CAS of 11, you looking at 11.7ns of latency... (11/993) x 1000 = 11.7ns

An improvement (albeit marginal) not doubt, but at almost 3x the cost, is it worth it? I was actually assuming that my 1333Mhz 8GB Mushkin kits were CAS 8, but just checked the packing now and they're actually CAS 9. I was kind of excited in the rush of the sale purchase to have gotten 1866Mhz performance at 1/3 the cost, but alas that would have been too good to be true. In any event, I'm not terribly disappointed in not having the fastest RAM kits. For my purposes, the jump to an SSD is the real improvement.

 

RAM from Samsung. Most reliable ever.

 

The performance difference? How did you measure it? If you mean daily usage then yes, you can't feel it most of the time. If you mean benchmark results and light games then there's a big difference - check the 3DMark results, and Everest (AIDA64) memory benchmark results. Asymmetric dual channel is obviously slower than symmetric dual channel in these benchmark tests.

In terms of hibernation and resuming performance, 6GB would be only 33% faster than 8GB. I'm using a Crucial M4 512GB SSD with 500MB/s sequential read and 300MB/s sequential write so it's about 26 sec hibernate and 16 sec resume for me.

 

Someone did this a while ago, he installed 1333 DDR3 RAM and ran a benchmark. He then installed 1600 DD3 RAM and ran a benchmark.

The result? Don't exactly remember the numbers but the increase was on the order of 5000 to 5001. Yeah not much of an increase. My advice, buy whichever RAM is cheaper.

 

Not to derail this thread too much, but just out of curiosity, you're not concerned about the lifespan of your SSD with the large writes caused by hibernation?

 

Why would I? Someone has done a stress test on the Intel X25-V, writing garbage into the disk for 24x7. After 300 days, the "Host writes" was 782.9TB, and the "Reallocated Sector Count" became 79. The SSD is still kicking.

I have regular backup from my SSD to my HDD every day, so I don't worry about data loss. By the time the SSD is worn out, it's supposed to be upgraded for sure.

 

For example in PCMark Vantage: 6GB = 10859, 8GB = 11299. SiSoftware Sandra memory bandwidth: 6GB = 16.69 GB/s, 8GB = 18.0 GB/s.

Here's the usage of my Intel 320 after about 5 months.

I hibernate an average of 3 times per day so that's about 15GB/day of writes. Multiply that by 150 days and I get 2.25TB, which is a small proportion of the total writes (I'd love to know that has clocked up all those writes).

John

 

Yeah you could call that "not a big difference". Indeed for daily usage I can't feel a difference if I don't measure it. However installing 2x4GB in symmetric would make it work optimally, while blocking any possible upgrade itch in the future, not having to mention that you might be unable to find another 4GB SODIMM of the same batch for the same timings (no, may not even be the same model).

Regarding your SSD: don't you worry about the 8MB bug of the Intel 320 Series? Lots of people reported data loss due to the 8MB bug AFTER the last firmware update.

 

No problem. I've already got 2 x 4GB modules which aren't from the same manufacturer but do have the same timings. These days there is no need to have matched pairs of RAM - the BIOS can figure out the fastest timings shared by both modules.

I haven't thought of updating the firmware since I got the SSD. I'll only consider it when Intel have fixed that bug.

John

 

I snagged the kingston 1866 memory...4gbx2, well worth the upgrade.

 

If you game, otherwise probably not. I doubt the Kingston would make much difference with multimedia duties- my main use.