MAXING OUT THE RAM ON AN ASUS M5A88-V EVO (BIOS 1801)
Reasons to consider ECC RAM if one's motherboard and CPU supports it:
"...As the graph above shows, ECC RAM has a much lower failure rate than non-ECC RAM. The ~1% failure rate of the Kingston non-ECC RAM is still very, very good (which is why we primarily use Kingston), but the ECC RAM is even better at an average .24% failure rate..."
November 5, 2013
Advantages of ECC Memory - Puget Custom Computers
http://www.pugetsystems.com/labs/articles/Advantages-of-ECC-Memory-520/
The use of ECC RAM forms the first line of defence against bit-squatting:
Defcon 19: Artem Dinaburg - Bit-squatting: DNS Hijacking Without Exploitation - YouTube
https://www.youtube.com/watch?v=lZ8s1JwtNas
10-26-2012
Is ECC RAM worth it for a desktop PC?
http://phoronix.com/forums/showthread.php?74764-Is-ECC-RAM-worth-it-for-a-desktop-PC
"...ECC support
The information in an ECC memory is stored redundantly enough to correct single bit error per memory word. Hence, an ECC memory can support the scrubbing of the memory content. Namely, if the memory controller scans systematically through the memory, the single bit errors can be detected, the erroneous bit can be determined using the ECC checksum, and the corrected data can be written back to the memory.
More detail
It is important to check each memory location periodically, frequently enough, before multiple bit errors within the same word are too likely to occur, because the one bit errors can be corrected, but the multiple bit errors are not correctable, in the case of usual (as of 2008) ECC memory modules.
In order to not disturb regular memory requests from the CPU and thus prevent decreasing performance, scrubbing is usually only done during idle periods. As the scrubbing consists of normal read and write operations, it may increase power consumption for the memory compared to non-scrubbing operation. Therefore, scrubbing is not performed continuously but periodically. For many servers, the scrub period can be configured in the BIOS setup program.
The normal memory reads issued by the CPU or DMA devices are checked for ECC errors, but due to data locality reasons they can be confined to a small range of addresses and keeping other memory locations untouched for a very long time. These locations can become vulnerable to more than one soft error, while scrubbing ensures the checking of the whole memory within a guaranteed time.
On some systems, not only the main memory (DRAM-based) is capable of scrubbing but also the CPU caches (SRAM-based). On most systems the scrubbing rates for both can be set independently. Because cache is much smaller than the main memory, the scrubbing for caches does not need to happen as frequently.
Memory scrubbing increases reliability, therefore it can be classified as a RAS feature...."
Memory scrubbing - Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Memory_scrubbing
From page 81 of the M5A88-V EVO manual:
"...Note: The 'Super' ECC mode dynamically sets the DRAM scrub rate so all of memory is scrubbed in 8 hours."
M5A88-V EVO user’s manual(English)
http://dlcdnet.asus.com/pub/ASUS/mb/SocketAM3+/M5A88-V_EVO/E6530_M5A88-V_EVO.zip
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john@john ~ $ sudo dmidecode | grep Product
[sudo] password for john:
Product Name: System Product Name
Product Name: M5A88-V EVO
john@john ~ $
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Being unable to find any evidence of 32 GB of ECC RAM working with an M5A88-V EVO, I choose to defer to the
"Maximum Capacity: 16 GB" reported by the 'board's BIOS via
sudo dmidecode -t memory even when there were only two DIMMs installed:
2 non-ECC, KVR16N11S8/4 DIMMs
john@john ~ $ sudo dmidecode -t memory
[sudo] password for john:
# dmidecode 2.12
SMBIOS 2.5 present.
Handle 0x0037, DMI type 16, 15 bytes
Physical Memory Array
Location: System Board Or Motherboard
Use: System Memory
Error Correction Type: None
Maximum Capacity: 16 GB
Error Information Handle: Not Provided
Number Of Devices: 4
Handle 0x0039, DMI type 17, 27 bytes
Memory Device
Array Handle: 0x0037
Error Information Handle: Not Provided
Total Width: 64 bits
Data Width: 64 bits
Size: 4096 MB
Form Factor: DIMM
Set: None
Locator: DIMM0
Bank Locator: BANK0
Type: Other
Type Detail: Synchronous
Speed: 1600 MHz
Manufacturer: Manufacturer0
Serial Number: SerNum0
Asset Tag: AssetTagNum0
Part Number: PartNum0
Handle 0x003B, DMI type 17, 27 bytes
Memory Device
Array Handle: 0x0037
Error Information Handle: Not Provided
Total Width: Unknown
Data Width: Unknown
Size: No Module Installed
Form Factor: DIMM
Set: None
Locator: DIMM1
Bank Locator: BANK1
Type: Unknown
Type Detail: None
Speed: Unknown
Manufacturer: Manufacturer1
Serial Number: SerNum1
Asset Tag: AssetTagNum1
Part Number: PartNum1
Handle 0x003D, DMI type 17, 27 bytes
Memory Device
Array Handle: 0x0037
Error Information Handle: Not Provided
Total Width: 64 bits
Data Width: 64 bits
Size: 4096 MB
Form Factor: DIMM
Set: None
Locator: DIMM2
Bank Locator: BANK2
Type: Other
Type Detail: Synchronous
Speed: 1600 MHz
Manufacturer: Manufacturer2
Serial Number: SerNum2
Asset Tag: AssetTagNum2
Part Number: PartNum2
Handle 0x003F, DMI type 17, 27 bytes
Memory Device
Array Handle: 0x0037
Error Information Handle: Not Provided
Total Width: Unknown
Data Width: Unknown
Size: No Module Installed
Form Factor: DIMM
Set: None
Locator: DIMM3
Bank Locator: BANK3
Type: Unknown
Type Detail: None
Speed: Unknown
Manufacturer: Manufacturer3
Serial Number: SerNum3
Asset Tag: AssetTagNum3
Part Number: PartNum3
john@john ~ $
In particular staying with a maximum of 16GB of RAM on the M5A88-V EVO, for the sake of assuring proper ECC functionality, is a good idea in view of the 13 BIOS updates this 'board received http://www.asus.com/Motherboards/M5A88V_EVO/HelpDesk_Download/ (most of which bore the description
"Improve system stability" that I interpret as meaning 'solved RAM problems') which were aimed at achieving system stability within the context of a maximum of 16GB of RAM.
4 ECC, KVR16E11S8/4 DIMMs
john@john ~ $ sudo dmidecode -t memory
[sudo] password for john:
# dmidecode 2.12
SMBIOS 2.5 present.
Handle 0x0037, DMI type 16, 15 bytes
Physical Memory Array
Location: System Board Or Motherboard
Use: System Memory
Error Correction Type: Single-bit ECC
Maximum Capacity: 16 GB
Error Information Handle: Not Provided
Number Of Devices: 4
Handle 0x0039, DMI type 17, 27 bytes
Memory Device
Array Handle: 0x0037
Error Information Handle: Not Provided
Total Width: 72 bits
Data Width: 64 bits
Size: 4096 MB
Form Factor: DIMM
Set: None
Locator: DIMM0
Bank Locator: BANK0
Type: Other
Type Detail: Synchronous
Speed: 1600 MHz
Manufacturer: Manufacturer0
Serial Number: SerNum0
Asset Tag: AssetTagNum0
Part Number: PartNum0
Handle 0x003B, DMI type 17, 27 bytes
Memory Device
Array Handle: 0x0037
Error Information Handle: Not Provided
Total Width: 72 bits
Data Width: 64 bits
Size: 4096 MB
Form Factor: DIMM
Set: None
Locator: DIMM1
Bank Locator: BANK1
Type: Other
Type Detail: Synchronous
Speed: 1600 MHz
Manufacturer: Manufacturer1
Serial Number: SerNum1
Asset Tag: AssetTagNum1
Part Number: PartNum1
Handle 0x003D, DMI type 17, 27 bytes
Memory Device
Array Handle: 0x0037
Error Information Handle: Not Provided
Total Width: 72 bits
Data Width: 64 bits
Size: 4096 MB
Form Factor: DIMM
Set: None
Locator: DIMM2
Bank Locator: BANK2
Type: Other
Type Detail: Synchronous
Speed: 1600 MHz
Manufacturer: Manufacturer2
Serial Number: SerNum2
Asset Tag: AssetTagNum2
Part Number: PartNum2
Handle 0x003F, DMI type 17, 27 bytes
Memory Device
Array Handle: 0x0037
Error Information Handle: Not Provided
Total Width: 72 bits
Data Width: 64 bits
Size: 4096 MB
Form Factor: DIMM
Set: None
Locator: DIMM3
Bank Locator: BANK3
Type: Other
Type Detail: Synchronous
Speed: 1600 MHz
Manufacturer: Manufacturer3
Serial Number: SerNum3
Asset Tag: AssetTagNum3
Part Number: PartNum3
john@john ~ $
As can be seen from the output of
sudo dmidecode | grep Product and
sudo dmidecode -t memory above, four of the following 4GB ECC DIMMS work with an M5A88-V EVO (BIOS 1801):
4GB Module - DDR3 1600MHz
Part Number: KVR16E11S8/4
Specs: DDR3, 1600MHz, ECC, CL11, 1R, X8, 1.5V, Unbuffered, DIMM
http://www.kingston.com/dataSheets/KVR16E11S8_4.pdf
KVR16E11S8/4
http://www.kingston.com/us/memory/search/?partid=KVR16E11S8/4
TIP: To get these DIMMs (and the non-ECC KVR16N11S8/4 DIMMs they replaced & which now reside on a GA-990XA-UD3 (rev. 1.x)) to show a speed of 1600 MHz I had to go into the BIOS setup and manually set the RAM to 1333 MHz, 9-9-9-24 or 8-8-8-24 (either of these timings works). If I left the BIOS RAM setting on Auto (target RAM speed of 1600 MHz, 11-11-11-28) or if I used a D.O.C.P. of 1600 MHz, 9-9-9-24 then
sudo dmidecode -t memory would report the RAM speed as being only 667 MHz.
And the reason why may have something to do with what
Tradesman1 shared in the following thread:
"Glad you said 'supposed' to, despite all the early advertising that the FX CPUs run DRAM 'native' at 1866, if you check AMD's own BIOS and Kernel Programming Guide, these MC (memory controllers) and CPUs are truly native 1333. The mutliplier on them was raised so they could handle 1866 out of the box, which reduced their OC ability to about 1GHz (a good 8350 can go from it;'s box 4 GHz to about 5GHz, Intel 3570K typically can go from 3.4 to about 4.8 or higher)....after I and many others went after AMD they changed the advertising to better reflect that that the FX's (and many lower end can't even run 1866) iin particular the 8350, 8150, 8320, etc are rated to run UP TO 1866 AT 1 STICK PER CHANNEL, that's 2 sticks total (and testing was done with 4 GB sticks which is 8GB total....so to keep them stable some need no additional voltage at all, but most need a bit of a boost to either/or the DRAM itself or the MC (memory controller) voltage, typically called CPU/NB... This is also why as more slots are populated i.e. running 4 sticks, the rated freq drops to 1600 and then to 1333, the MCs true 'native' freq... see the link below
http://support.amd.com/en-us/kb-articles/Pages/ddr3memoryfrequencyguide.aspx "
Can't run memory at 1866mhz - RAM - Memory
http://www.tomshardware.com/answers/id-1720598/run-memory-1866mhz.html
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The DDR3 32GB ECC RAM kit which Kingston recommends for current (usually Asus) AM3+ motherboards which support ECC RAM:
32GB Kit (4x8GB) - DDR3 1600MHz
Part Number: KVR16E11K4/32
Specs: DDR3, 1600MHz, ECC, CL11, X8, 1.5V, Unbuffered, DIMM, 240-pin
http://www.kingston.com/dataSheets/KVR16E11K4_32.pdf
Memory Search | Options
http://www.kingston.com/us/memory/search/options/
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DDR3 memory frequency guide
http://support.amd.com/en-us/kb-articles/Pages/ddr3memoryfrequencyguide.aspx