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What's the best memory RAM for my computer?

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May 19, 2009 12:02:44 PM

Hi all, Iam Mário from Brazil.

I just bought a new computer, but i'd like to put the fastest memory, i dont mind with price.

So i wonder whats the best nowdays? i was thinking in put corsair dominator 1066 Mhz but i heard that my motherboard doesnot support 8gb ram at this clock.

So, please help me. :) 


Motherboard > asus >>m3a78
Processor > AMD phenom II 940 3.0Mhz

More about : memory ram computer

a b } Memory
a b V Motherboard
May 19, 2009 1:23:12 PM

I do not believe Phenoms support speeds greater than 800Mhz at the quantity you are looking to use. Please check with your motherboard maker as to what they do support.
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May 19, 2009 2:23:23 PM

hmmm but badge, your motherboard is m3a78-em, mine is just m3a78.

i think theres a diference well i dunno.

i heard that my motherboard wont be able to use 8gb ddr 2 at 1066.

but well iam ok with this, i know that there are very good ddr2 800 high performance.

so which one shuld i buy? :) 
May 19, 2009 2:29:32 PM

your saying that i could put 8gb of this memory on my model of motherboard and this would work at 1066?
May 19, 2009 2:32:44 PM

i dont undestand this

"Due to AMD CPU limitation, DDR2 1066 is supported by AM2+ CPU for one DIMM per channel only. Please refer to www.asus.com or user manual for Memory QVL."
a b } Memory
a b V Motherboard
May 19, 2009 2:33:24 PM

So, the 770 chipset will not support more than 2 DIMMs at 1066MHz. My board has the 780 which supports 8 gigs at 1066MHz. just fine.
a b } Memory
a b V Motherboard
May 19, 2009 2:38:24 PM

Your MB will support 8 GBs of RAM no matter if you install PC2 8500 or PC2 6400. But the chipset will not attain PC2 8500 1066MHz. speeds. Bottom line, you can use 8 GBs DDR2, but the top speed is limited when doing so. PC2 8500 is simply overclockable PC2 6400 800Mhz. RAM.
a b } Memory
a b V Motherboard
May 19, 2009 2:39:58 PM

rabujento said:
your saying that i could put 8gb of this memory on my model of motherboard and this would work at 1066?


Your MB will support 8 GBs of RAM no matter if you install PC2 8500 or PC2 6400. But the chipset will not attain PC2 8500 1066MHz. speeds. Bottom line, you can use 8 GBs DDR2, but the top speed is limited when doing so. PC2 8500 is simply overclockable PC2 6400 800Mhz. RAM.
May 19, 2009 2:45:41 PM

thanks mate. so do you think is worth to buy the best ddr2 800 and then make a overclock ?
a b } Memory
a b V Motherboard
May 19, 2009 2:47:14 PM

rabujento said:
i dont undestand this

"Due to AMD CPU limitation, DDR2 1066 is supported by AM2+ CPU for one DIMM per channel only. Please refer to www.asus.com or user manual for Memory QVL."


If all four DIMM slots are populated (8 GBs uses all four) PC2 8500 1066MHz. is not an attainable speed or data transfer rate. But, all four DIMM slots can be populated (the MB will support 8 GBs) at a lower data transfer rate than 1066MHz., say 800 MHz. for example. It does not mean that PC2 8500 rated DIMMs will not work on the MB. They will work, and 8 GBs worth, but not at their rated speed of 1066MHz.
a b } Memory
a b V Motherboard
May 19, 2009 2:54:12 PM

rabujento said:
thanks mate. so do you think is worth to buy the best ddr2 800 and then make a overclock ?



Haha! Yeah just buy 8 GBs PC2 6400 800MHz. for that board. BIOS will have a setting for 800MHz. Should work without issue in that configuration. The PII 940 has an unlocked multiplier, which I use to overclock. I then set my RAM speed to 1066MHz. in BIOS, 8 GBs at 1066MHz. with the processor at 3.6GHz. via the unlocked multiplier. Your board will not run at 1066MHz. like this with 8GBs. But 8 gigs will run at something less than 1066MHz.
May 19, 2009 2:56:23 PM

badge, what ddr2 800 you recommend for me?
a b } Memory
a b V Motherboard
May 19, 2009 3:14:25 PM

I had 8 GBs of this PC26400 running fine in my board. But, even by OCing the system BUS these kits would not reach 1066MHz. They would run at around 900MHz. or slightly less with the board which is pretty well for price/performance.

http://www.newegg.com/Product/Product.aspx?Item=N82E168...
a b } Memory
a b V Motherboard
May 19, 2009 3:29:15 PM

BTW, if that MB is running, be sure to update to the latest BIOS version which will support the PII 940.
a b } Memory
a b V Motherboard
May 19, 2009 5:28:13 PM

This stuff's pretty nice:
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Even if you can't get it to run at 1066, it'll probably run 800MHz with CAS 4 or lower without much extra voltage. Besides, I would be surprised if you couldn't get 1066MHz working with 8 gigs. My motherboard claims support for only one DDR3-1600 DIMM per channel, but I'm running 12 gigs (2 per channel) at that speed with tighter than rated timings without difficulty.

Otherwise, this is also good stuff:
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
May 19, 2009 5:53:03 PM

iam about to buy those corsair i showed above. do you think they are good for overclocking?
a b } Memory
a b V Motherboard
May 19, 2009 6:14:20 PM

Not bad, but not as good as the G.Skill that I linked to.
May 19, 2009 6:42:14 PM

hmmm cool but i think ill buy the corsair 1066 dominator anyway, ill try to make the 8gb run at 1066 and even if they dont, ill w8 for any update in bios or something, and then if they update bios..ill be already ready to use the 1066 what do you think?
a b } Memory
a b V Motherboard
May 19, 2009 6:58:51 PM

That should work. Dominator is good memory.
a b } Memory
a b V Motherboard
May 19, 2009 7:24:16 PM

If Ocing by the unlocked multiplier, the RAM does not move to higher clocks because the system BUS is not OC'ed, the CPU multiplier is. Anyway, if OCing by increasing the BUS speed, the G. Skill PC26400 RAM I linked will run at near 900MHz. @ 4-4-4-12. That's why everyone on the 'egg gives it such a high rating.
May 19, 2009 8:45:33 PM

iam going for those corsair dominator.. allowed? ehehe
a b } Memory
a b V Motherboard
May 19, 2009 8:53:18 PM

So you plan on overclocking? Overclocking by raising the system BUS? Or overclocking by raising the CPU's unlocked multiplier? Or not overclocking at all?
May 19, 2009 9:02:07 PM

hmmm iam planning to overclock..what would be the best way?
a b } Memory
a b V Motherboard
May 19, 2009 9:06:57 PM

If you are overclocking by the CPU's multiplier, the RAM is set at 800MHz in BIOS and does not 'overclock' along with the CPU. This is because the system BUS has not been increased taking the RAM to higher speeds with it. This is the way I overclock to 3.6GHz. with the PII 940. I overclock with the CPU multiplier. Tyhen in BIOS using the 1066MHz. setting for my RAM speed.

If you overclock the system BUS speed, it takes the RAM to higher speeds along with the CPU. You are probably confused by now. 8)
May 19, 2009 10:18:41 PM

hmm i got you. i changed the 200mhz X 15 to 220 X15 now my memorys works at 880 :) 

but it is cheap kingston.

then if i buy those corsair and with no overclock the pc recognize it as 800..i just do a over and it goes to 1066 easy..right?
May 19, 2009 10:28:16 PM

btw are you using memories ganged or ungaged?
a b } Memory
a b V Motherboard
May 19, 2009 11:11:04 PM

Unganged. I doubt the Corsair would run at 1066MHz. even if the timings were loosened to 5-5-5-15. Besides, your chipset will not support 8 Gigs (4 DIMMS) at 1066MHz., so you likely wont get there.

Quote:
i changed the 200mhz X 15 to 220 X15 now my memorys works at 880 :) 


With the PII 940 instead of raising the BUS to 220 x 15 you could leave the BUS at 200Mhz. and adjust the CP multiplier leaving the RAM at 800MHz. You could overclock the CPU to 3.6GHz or more with cooling and have the RAM running at 800MHz. I do this with PC2 8500 at 1066MHz. But my board supports that transfer rate of 1066MHz., 8.5GB/sec. You board does not with 4 slots populated. :) 

200MHz. x 16 = 3.2GHz.
200 x 17 = 3.4GHz
200 x 18 = 3.6GHz.

When you adjust the CPU multiplier the BUS is left at 200MHz. This way the RAM is not 'overclocked' by increasing the BUS. The BUS is left at 200MHz.
May 19, 2009 11:27:10 PM

hmmm lol ok..so ill just buy an decent memory ddr2 800..and put 8gb.. what you think?
a b } Memory
a b V Motherboard
May 19, 2009 11:44:34 PM

LOL. Yeah, that's what I was thinking! But the Corsair is nice RAM will surely give you 4-4-4-12 timings. Like I said, I originally had 8 gigs of the G. Skill PC2 6400 800Mhz. in the system. That RAM would not run at 1066MHz. I later installed the PC2 8500 for the purpose of using the CPU multiplir and simply setting the RAM speed to 1066Mhz. in BIOS. It's a great system! Micro build for small dollars. Very effective! 8)
May 19, 2009 11:51:39 PM

ok. ill look for the best corsair, brazil sucks for buy those things..too expensive and we dont have many options. so what memory ddr2 you recommend boss? hehehe
a b } Memory
a b V Motherboard
May 19, 2009 11:55:04 PM

Multiplier at 18 x 200MHz. 3.6GHz.

a b } Memory
a b V Motherboard
May 19, 2009 11:57:29 PM

Memory at 1066MHz.

a b } Memory
a b V Motherboard
May 19, 2009 11:59:19 PM

Well, PC2 6400 rated at 2.0v or less with timings of 4-4-4-12, even 5-5-5-15 is ok.
May 20, 2009 12:00:05 AM

so you mean to me get a ddr800 and set on setup to 533mhz..then it would work at 1066?
a b } Memory
a b V Motherboard
May 20, 2009 12:04:30 AM

Well, hard to find 800Mhz. RAM that will run at 1066MHz., no guarantee and every system is different. And if you populate all four slots, your board will not run the RAM at 1066MHz. or 8.5GB/sec transfer rate. So, if using 8GB, looks like PC2 6400 4 x 2 GB would be the solution. Then with PII 940 use the unlocked multiplier as described and set the RAM to 800MHz. in BIOS and know the RAM will run at 800MHz. and not have to clock faster to keep up with the CPU being overclocked with the system BUS. So, yeah, I mean the Corsair is some nioce RAM. Just look for 2,0v or less to achieve 800MHz. at 4 or 5CAS.
a b } Memory
a b V Motherboard
May 20, 2009 12:06:07 AM

Capacidade:2GB (2 x 1GB)Velocidade:800 Mhz (PC2 6400)Latência CAS:5Temporizações:5-5-5-12Voltagem:1.9V

Those are 2 x 1 GB. You want 2 x 2 GB and two kits for 8GB. You are using a 64 bit operating system right?
May 20, 2009 12:14:18 AM

not yet ^^ but ill install vista 64...and ye my mistake those are 2x1..aff lol

btw i found a Corsair Ddr2 Xms2 Dhx 4gb C4 (2 X 2 Gb) Pc6400 Dual Channel with 4-4-4-12 latency..but 2.1V is this ok?
a b } Memory
a b V Motherboard
May 20, 2009 12:19:51 AM

As long as your MB has voltage adjustments up to 2.1v (or a little better with 8 GBs.). ASUS is very good and my board has plenty of adjustment for the RAM voltage. So sure, Corsair has a limiuted lifetime warranty. Have you ever checked the Crucial website if newegg is not possible? Run your board through their RAM configurator. I believe they will ship to you is why I mention it. But, sure the Corsair you chose should work just fine.

http://www.crucial.com/
a b } Memory
a b V Motherboard
May 20, 2009 12:21:28 AM

Forgot to mention, BIOS will default the PC26400 to 1.8v in most instances. So, use 1 DIMM in slot 1 to load up everythin, OS etc., then add the other 6 GB later after SP1 and all updates and system drivers have been installed. You will have to go into BIOS and adjust the RAM voltage manually to 2.1v.
May 20, 2009 12:22:06 AM

ye my MB has the option to adjust the voltage of memory.

the bad thing at buying in a site out of brazil..is that i need to pay the tax when it come..and it is almost same of the product lol
a b } Memory
a b V Motherboard
May 20, 2009 12:24:20 AM

Consider Crucial' website. Maybe run the board through that memory configurator on the home page for suggestions.

http://www.crucial.com/
May 20, 2009 12:25:24 AM

sure. btw i sent u a PM
a b } Memory
a b V Motherboard
May 20, 2009 12:42:27 AM

badge said:
Unganged. I doubt the Corsair would run at 1066MHz. even if the timings were loosened to 5-5-5-15. Besides, your chipset will not support 8 Gigs (4 DIMMS) at 1066MHz., so you likely wont get there.

I still think that he could get 4 DIMMS working at 1066 with a bit of effort. As I said before, the x58 only supports one XMP DIMM (>1333MHz) per channel (up to 3 DIMMS total), but plenty of people (myself included) are running systems with 6 DIMMS at >1333MHz anyways. Maybe the AMD system is more difficult to push past the official amount supported, but I would be quite surprised if you couldn't get it to work at all.
a b } Memory
a b V Motherboard
May 20, 2009 12:46:27 AM

OP do you have the most recent, current, BIOS and does the BIOS offer the 1066MHz. setting for the RAM? I doubt te Corsair PC26400 would run at 1066MHz. if that option is available. My PC26400 would not.
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