Buy pair or single RAM bank?

[hyde]

I found this as a set, for $35
Crucial 8GB (2 x 4GB) DDR3 PC3-10600 1333MHz 204-pin SODIMM Laptop Memory - CT2KIT51264BC1339
http://www.buy.com/loc/holiday-supersto ... =214920883

I understand that Lenovo supplies 1333Mhz as default, so getting a pair would make no sense or does it?
Is there anything different with Lenovo's RAMs that may cause issues? Single RAM bank costs about $15 to $20 vs Pair for $30 to $35.

[Bánh mì]

I have an x201 with i5 and from everything I read top speed is 1067Mhz so I got that instead. My default was 1067Mhz. I think only the i7 can take the 1333Mhz and utilize it althought it will install in my setup. So i bought the PC8500 instead after much delibration.

[hyde]

Thanks for the reply, it would be really strange for Thinkpad to install 1333 if the system board only supports up to 1067, because 1333 is most likely more expensive. Unless they scored 1333's at a much better price.

Looking at HWinfo, it really runs at 1333MHz, so there is no limitation in this model.

[Bánh mì]

You have the 2540M whreas mine is a 540M though both are i5s- one annual iteration newer. Yours does support the higher frequency so I would go for it. I went with the lower clockspeed despite a slightly higher price since I didn't want to tinker with someting different from what I have now. HP has been known to overspec RAM. Don't think Lenovo does it as in my case it came with the 1067Mhz.

[hyde]

There was a discussion about higher clock RAM and if it actually uses more battery, and if the speed will compensate for the battery consumption, etc.. I can't find that topic, anyway, if anyone has a good price for 4GB module, shoot this way.
I will just buy a 4GB and call it a day since we cannot get 8GB unless we break the bank.

[azX32]

Is there anything different with Lenovo's RAMs that may cause issues?

In a word, no.

The RAM Lenovo uses varies. I've seen Hynix a lot; my X220 came with Samsung. I've never had a problem mixing any other brand with what Lenovo installs - including my X220 with 4GB Samsung + 4GB Patriot. As with any RAM you buy, you can run Memtest after installing it to check for reliability. There's also a memory stress test within ThinkVantage Toolbox, which I've never run, and it may be identical to Memtest.

BTW the RAM in the X220 is 1333MHz, regardless of i3, i5, or i7 processor.

[Bánh mì]

I've seen both Hynix and Micron in Thinkpads. I doubt any PC company would only use a single supply source. For post purchase upgrades, Crucial is a popular choice. I've never had any issues with their product and its just the consumer brand side of Micron. So its a solid bet IMO.

[hyde]

According to HWinfo, it uses Samsung:

Code: Select all

Row: 0 - 4096 MB PC3-10600 DDR3 SDRAM Samsung M471B5273DH0-CH9 ------------
 [General Module Information]
  Module Number:                          0
  Module Size:                            4096 MBytes
  Memory Type:                            DDR3 SDRAM
  Module Type:                            SO-DIMM
  Memory Speed:                           666.7 MHz (PC3-10600)
  Module Manufacturer:                    Samsung
  Module Part Number:                     M471B5273DH0-CH9
  Module Revision:                        0
  Module Serial Number:                   1095319911
  Module Manufacturing Date:              Year: 2011, Week: 24
  Module Manufacturing Location:          2
  SDRAM Manufacturer:                     Samsung
  Error Check/Correction:                 None
 [Module characteristics]
  Row Address Bits:                       15
  Column Address Bits:                    10
  Number Of Banks:                        8
  Module Density:                         2048 Mb
  Number Of Ranks:                        2
  Device Width:                           8 bits
  Bus Width:                              64 bits
  Module Nominal Voltage (VDD):           1.5 V
 [Module timing]
  Minimum SDRAM Cycle Time (tCKmin):      1.500 ns
  CAS# Latencies Supported:               5, 6, 7, 8, 9
  Minimum CAS# Latency Time (tAAmin):     13.125 ns
  Minimum RAS# to CAS# Delay (tRCDmin):   13.125 ns
  Minimum Row Precharge Time (tRPmin):    13.125 ns
  Minimum Active to Precharge Time (tRASmin): 36.000 ns
  Supported Module Timing at 666.7 MHz:   9-9-9-24
  Supported Module Timing at 533.3 MHz:   7-7-7-20
  Supported Module Timing at 400.0 MHz:   6-6-6-15
  Supported Module Timing at 333.3 MHz:   5-5-5-12
  Minimum Write Recovery Time (tWRmin):   15.000 ns
  Minimum Row Active to Row Active Delay (tRRDmin): 6.000 ns
  Minimum Active to Active/Refresh Time (tRCmin): 49.125 ns
  Minimum Refresh Recovery Time Delay (tRFCmin): 160.000 ns
  Minimum Internal Write to Read Command Delay (tWTRmin): 7.500 ns
  Minimum Internal Read to Precharge Command Delay (tRTPmin): 7.500 ns
  Minimum Four Activate Window Delay Time (tFAWmin): 30.000 ns
 [Features]
  On-die Thermal Sensor (ODTS) Readout:   Not Supported
  Auto Self Refresh (ASR):                Not Supported
  Extended Temperature Refresh Rate:      Not Supported
  Extended Temperature Range:             Supported
  Module Temperature Sensor:              Not Supported
  Module Nominal Height:                  29 - 30 mm
  Module Maximum Thickness (Front):       1 - 2 mm
  Module Maximum Thickness (Back):        1 - 2 mm

This is what is coming up at Amazon. It doesn't seem to be an exact match but looks like most Lenovo users went with this module.
http://www.amazon.com/Samsung-MV-3T4G4- ... 713&sr=1-1

[Bánh mì]

8GB 2x4 for $45 at Crucial about a week ago. Will work on your x220. Don't be hung up on getting Samsung. Crucial is Micron and that is also used in Thinkpads along with Hynix.