RAM voltage
in [Computer]
|
Prev: Lenovo - XP - Win7
Next: OS for 4GB RAM
From: JD on 2 Apr 2010 14:24 On 02/04/2010 6:53 PM, James D. Andrews wrote: > "JD"<No.Reply(a)Sorry.com> wrote in message > news:4bb62175$0$2522$da0feed9(a)news.zen.co.uk... >> On 02/04/2010 4:17 PM, James D. Andrews wrote: >>> "James D. Andrews"<jamesdandrews(a)att.net> wrote in message >>> news:hp51g1$2516$1(a)adenine.netfront.net... >>>> Trying to choose RAM for a new mobo - a BIOSTAR MCP6P M2+ running an AMD >>>> Sempron. > SNIP SNIP > >>>> So, the problem I'm having in selection is picking RAM with >>>> consideration >>>> to voltage. >>>> > SNIP SNIP > Do I need 1.95 and above or 1.95 and below? >>>> >>>> The long list of chips that meet my other needs and qualifications >>>> ranges >>>> from 1.8V - 2.2V > >>> Whoops! I forgot to mention, I'm looking at DDR2, either 800 or 1066 >>> 4GB (2x2GB) >> The manual for your Mobo: >> http://www.biostar-usa.com/upload/Manual/N61PB-M2S_090918_B.zip >> >> Your motherboard supports 1.95v, 2.0v, 2.05 and 2.1 the default voltage is >> 1.95v >> >> I can recommend the OCZ DDR2 800Mhz Platinum XTC 2Gb Kits (I have 2 of >> them, 4gb in the media centre downstairs) part number OCZ2P8002GK, Voltage >> 2.1v, and I see they have come down in price also. >> >> JD > > Thanks JD > You come through again. > > The OCZ Platinum was actually at the top of my list, nice to know you > recommend it. > > However, I hate to be a pest, but ... > > I was reading through a gazillion sites today and came across a possible > problem: > One site said the Sempron will not support memory more than 667s. Another > said 800s. Another said 400s. But I've read of people using 1066s. > > AMD site is good for bringing on a mental breakdown. > > I'm so confused. Do you know what my Sempron 140 Sargas will support for > memory? > > > > > > > > > --- news://freenews.netfront.net/ - complaints: news(a)netfront.net --- I'd say its more to do with the motherboard, if the motherboard supports the ram it should work fine, did a quick search and it seems that the most popular ram sold with that CPU is the 800Mhz variety, you should be safe with that. JD
From: James D. Andrews on 2 Apr 2010 17:59 "Paul" <nospam(a)needed.com> wrote in message news:hp5bvr$hcn$1(a)news.eternal-september.org... > James D. Andrews wrote: >> "James D. Andrews" <jamesdandrews(a)att.net> wrote in message >> news:hp51g1$2516$1(a)adenine.netfront.net... SNIP SNIP >>> A couple people stated that the voltage defaults to 1.95V >>> Do I need 1.95 and above or 1.95 and below? >>> The long list of chips that meet my other needs and qualifications >>> ranges from 1.8V - 2.2V >> Whoops! I forgot to mention, I'm looking at DDR2, either 800 or 1066 >> 4GB (2x2GB) > > All memories "operate" at 1.8V (for DDR2), because that is the JEDEC > agreed standard. Enthusiast memory may fail to meet timing at 1.8V, > so the manufacturer may say "meets timing at 2.1V". But all DDR2 should > do something, when 1.8V is applied. > > You would hope, that if a memory product is in that situation, that the > SPD would not call up the specified timings. For example, say a memory was > DDR2-1066 6-6-6-18 at 2.1V. For that memory to start without crashing, > the "top speed" shown in the SPD might be DDR2-800 6-6-6-18, which would > represent a slightly relaxed set of values (easier for the memory to > meet). > That allows the user to get into the BIOS, the first time the product is > used. If the user never entered the BIOS, then the product would stay > running at DDR2-800 forever. > > Once the user is in the BIOS, they look at the piece of paper that > accompanied the product, that claimed it was DDR2-1066 6-6-6-18 at 2.1V. > The user would then dial those values in manually, and test. In other > words, the SPD is designed to *not* represent the spec for the RAM, > in order that the motherboard will start up the first time. That is > to get around the "startup problem". > > Your board supports: 1.950V (default), 2.000V, 2.050V, 2.100V. > > It is going to start at the default value the first time, and then you can > crank it up. > > I would not buy a memory product with a stated voltage need of > more than 2.1V to meet timing, as your board doesn't go any higher. > > And if you bought a 1.95V memory, that would guarantee the stick > would meet timing, no matter what is stored in the SPD. > > This kit is in the right ballpark. The difference between 1.95 and 2.00 > is small enough, that this is likely to work no matter what is in the > SPD chip on the DIMM. > > Cas Latency: 6 Voltage: 2.0V Dual Channel 6-6-6-18 > F2-8500CL6D-4GBNQ > http://www.newegg.com/Product/Product.aspx?Item=N82E16820231226 > > and this one needs too much voltage to meet its specified timing, > so you'd need to relax the timing or frequency to make it work > on your 2.1V max board. > > Cas Latency: 5 Voltage: 2.2V - 2.4V Dual Channel 5-5-5-15 > GX24GB8500C5UDC > http://www.newegg.com/Product/Product.aspx?Item=N82E16820144255 > > Now, I found this comment on another site for the GX24GB8500C5UDC product. > > "The SPD's default this RAM to safe DDR800, but with a few tweaks in > the BIOS, > we are smokin" > > That means the 2.2V DDR2-1066 RAM, starts at DDR2-800, and by doing so, > it would need less voltage to start. It would likely work well enough that > it would start right away at your default 1.95V. But the problem is, > your board only goes to 2.1V, so you couldn't dial in the exact > numbers on the box. If you wanted to use that 2.2V RAM, perhaps > you'd set the timing to 5-6-6-18 or something and retest. Then > try 6-6-6-18 and test again with memtest86+ and so on. > > The reason there is a range of voltages on that second product, is > the first voltage is the one to meet timing. The second voltage > is the maximum recommended voltage. And since you can download > memory datasheets from the memory chip manufacturers, you can > see that their "absolute maximum" voltage roughly agrees with > what the DIMM maker is listing. > > When a single voltage is listed, like the 2.0V RAM, they aren't > listing the absolute max. If you can see what brand of chips is > being used, you can look up the absolute max for them yourself. > > Some enthusiast memory, contains additional information in the SPD. > The JEDEC spec, doesn't allow for "enthusiast voltage" as a parameter. > The specification extensions (there are a couple pseudo-standards), allow > both timing and voltage to be specified. But the motherboard BIOS > must support such a scheme, for it to work. If you mixed such > a stick, with a BIOS that doesn't read that info, you'd be no > better off than before. Or perhaps even worse off, depending on > how cleverly the SPD is coded. > > With the conventional SPD scheme, as long as they relax the timing, > and don't write the rated values in the SPD, then the user can dial > in the values manually. That defeats the purpose of the SPD (which > is to automate the process), but solves the problem of enthusiast > products needing way too much voltage. > > On "non-enthusiast" RAM, say a product that claims to run at 1.8V, > the operation at 1.95V is not going to hurt it. That is far enough > below "absolute max" to not affect service life. And the little bit > of extra voltage helps ensure the motherboard doesn't crash when it > starts up the first time. > > This one, for example, is specified at 1.8V, which means it is going > to start in whatever motherboard it is plugged into. One user got this > to work on an Intel board, but not an AMD. Go figure... Always > read the reviews, for any quirks. It is how I shopped for RAM > the last time, and ended up selecting a different brand as a > result. If the reviews show a lot of DOAs or the like, then > why bother ? The only way a manufacturer can cut costs, is to > reduce test time. So the review comments are important. Don't > just read the summary numbers at the top, read the individual > comments. For example, if a memory product "burned my DIMM slot", > I wouldn't touch the product with a barge pole, no matter how many > other glowing reports there were. > > http://www.newegg.com/Product/Product.aspx?Item=N82E16820148249 > > Paul Paul, Thank you very much. And yeah, I always use the reviews to make my decisions. I don't want to pick a product of any kind that 4/5 people hate, and so on. I also pay attention to what the odd complaints are, such as when someone complains about a product not working the way they want it to when they knew ahead of time it doesn't work that way (e.g., complaining the single core processor they bought on sale isn't quad). Thanks --- news://freenews.netfront.net/ - complaints: news(a)netfront.net ---
From: Paul on 2 Apr 2010 22:39 James D. Andrews wrote: > > Paul, > Thank you very much. > > And yeah, I always use the reviews to make my decisions. I don't want to > pick a product of any kind that 4/5 people hate, and so on. > > I also pay attention to what the odd complaints are, such as when someone > complains about a product not working the way they want it to when they knew > ahead of time it doesn't work that way (e.g., complaining the single core > processor they bought on sale isn't quad). > > Thanks > With regard to your other comments about the AMD site, and figuring out what a processor supports - I agree, their documentation is a shambles. ******* AMD processors have the memory controller on the processor itself. The speed handled is a family characteristic. A general trend, is if the motherboard has four memory slots, the two slot configuration usually runs one frequency step above what the four stick configuration can do. Your board only has two slots, so that is the only configuration choice you've got. You also have the limitation, of up to a 95W processor. The Vcore on the Biostar motherboard, only has three phases. Now, if they didn't support split plane power (separate power for IMC and Vcore), I suppose then the board would effectively be AM2, and then the memory would be stuck at DDR2-800. If one phase powers the IMC, and two phases power Vcore, then the next speed up should be possible. http://www.biostar.com.tw/app/en/mb/content.php?S_ID=370# This AM3/AM2+/AM2 has DDR2 DIMM slots, and the description says http://www.etccomputer.ca/eShop/product_details.asp?productid=6356 "*Due to AMD CPU limitation, DDR2 1066 is supported by AM2+/AM3 CPU only." And that motherboard has only two DIMM slots, which is why they don't have to distinguish between two slots versus four slots. This AM3 board with DDR3 memory... http://www.etccomputer.ca/eShop/product_details.asp?productid=6737 "Memory 2 x DIMM, Max. 8 GB, DDR3 1800(O.C.)/1600(O.C.)/1333/1066" So in that case, DDR3-1333 is max speed with two sticks, and higher speeds are by overclocking. If you have an AM2 processor, that kind of processor has one power plane for both Vcore and the memory. AM2+ and AM3 are split plane. AM2 supports DDR2-800. AM2+ goes to DDR2-1066, AM3 goes to DDR3-1333. Your Sargas Sempron 140, is AM3. On a DDR2 motherboard, it should be able to do DDR2-1066 (while on an AM3 motherboard with DDR3 slots, it would be DDR3-1333 without overclocking. If the processor was plugged into an older AM2 motherboard, the motherboard would need a BIOS update, and the RAM interface would likely run DDR2-800. The thing is, you don't have to worry. You can buy DDR2-1066 RAM, and it will happily run at DDR2-800. So it isn't like you have to throw the RAM away, if my previous paragraphs are wrong. ******* In the reviews here, for the Sempron 140, I can see at least a couple people using DDR2-1066 with that processor. And I don't see any comments about being stuck at DDR2-800. Mind you, the difference could be the motherboard they're using. http://www.newegg.com/Product/ProductReview.aspx?Item=N82E16819103698 ******* Now, if we look at reviews for your motherboard. http://www.newegg.com/Product/ProductReview.aspx?Item=N82E16813138111 "Pros: Supports DDR2-1066 RAM ******************** this wasn't stated in the item description" That implies it does have split plane powering (or it is cheating and taking chances :-) ). So, go for it! While some people have succeeded at unlocking the second core in the Sempron 140, I would not count on that. In terms of applications, if a family member wanted a computer only for Microsoft Office, I wouldn't feel too badly about giving them a single core solution. But if you have video playback as a part of the plan, I'd want a bit more headroom, and a dual core might be a bit smoother. This one is $59 and includes a heatsink/fan. http://www.newegg.com/Product/Product.aspx?Item=N82E16819103688 Paul
From: James D. Andrews on 6 Apr 2010 16:02
"Paul" <nospam(a)needed.com> wrote in message news:hp69pn$g3p$1(a)news.eternal-september.org... > James D. Andrews wrote: > SNIP SNIP SNIP > While some people have succeeded at unlocking the second core in the > Sempron 140, > I would not count on that. In terms of applications, if a family member > wanted a computer only for Microsoft Office, I wouldn't feel too badly > about giving them a single core solution. But if you have video playback > as a part of the plan, I'd want a bit more headroom, and a dual core > might be a bit smoother. > > Paul Yeah, I saw that about unlocking, but I'm neither that tech savvy nor can I afford to experiment with a processor. I like to use products as they are intended, avoid the "what if something goes wrong" issue. It won't be a gaming or audio/video computer, just office and home use, some downloading, so I could go with the less expensive single-core without much concern. This combo will give me nearly 3x the processor and 8x the RAM I currently use in my office, so I'm a happy camper. My next issue is deciding on a hard drive next month. As a general rule, whatever I buy will go on sale shortly after my purchase. --- news://freenews.netfront.net/ - complaints: news(a)netfront.net --- |