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RAM DDR2 vs DDR3 vs. 800mghz vs 1333, which one?

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June 8, 2008 2:47:45 PM

Hi, I'm buying a Q9550 with 8 Gig of Ram (plus Vista 64)... does anyone know in the ins and outs of DDR2 vs DDR3 RAM and the 800ghz vs. 1333 RAM options - the Q9550 has a 1333 mghz fsb (quad pumped) capability, and all I want is super fast load times/ multitasking..... so should I get DDR2 or DDR3 type RAM and when I've chosen one what mghz should I go for ie. DDR2 800mghz, DDR2 1333 mghz, DDR3 800 mhz or DDR3 1333 mhz???
(I'm not really looking to OC at this point, more after an untampered/ stock super quick rig)??? any suggestions much appreciated : )
June 8, 2008 2:50:09 PM

I'm 75% performance oritntated, 25% price orientated....
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June 8, 2008 3:41:09 PM

Right now, DDR3 has no real advantage over DDR2.
The higher bandwidth is pretty much negated by the slower latencies.
You will have a very tough time getting more than 2 sticks to run at 1333mhz. More than 2 sticks of memory...might as well just stick to 800mhz DDR2.
You won't be able tell the difference between any of these anyway.
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June 8, 2008 3:59:14 PM

Thanks jit, is there any brand of DDR2 ram thats better than others? I heard that i should get sticks that are low speeds like 11444 or something (dont really understand what was being said)...
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June 8, 2008 4:06:41 PM

Get some DDR2 800 RAM. If you have a DDR3 motherboard and need only 2GB (8GB DDR3 is very expensive btw, and I am not sure if many motherboards support 8GB DDR3) consider this DDR3:
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
It's about the same price as some 4GB DDR2 800.

I still recommend you get good DDR2 800 from a good manufacture like, Crucial (notably the Crucial Ballastix), Corsair, Patriot, G.Skill. If going with DDR2 1066 be warned there may be compatibility issues.
June 8, 2008 4:12:16 PM

simon1980111 said:
Thanks jit, is there any brand of DDR2 ram thats better than others? I heard that i should get sticks that are low speeds like 11444 or something (dont really understand what was being said)...


the low speeds are the Latencies...like 4-4-4-12...I think what that means is the number of clock cycles it takes to get to 800Mhz or maybe to process information...but if you look at the Latencies of DDR3 you will notice some of them are like 9-9-9-20s...which is a huge reason not to buy DDR3 other than the price
June 8, 2008 8:01:34 PM

simon1980111 said:
Hi, I'm buying a Q9550 with 8 Gig of Ram ... - the Q9550 has a 1333 mghz fsb (quad pumped) capability, and all I want is super fast load times/ multitasking......

Load times will depend on the speed of your hard drive; consider buying 4 drives for a RAID 0+1 configuration, or just two drives for RAID 0 if you don't mind living dangerously.
As far as current Intel designs go, memory throughput is limited by the FSB speed. With memory running in dual-channel mode, running the memory bus at 1/2 the FSB speed will match the FSB throughput. For example, a memory bus running at DDR2-667 will use all the capacity of an FSB running at 1333MHz.
It's best to get RAM rated at DDR2-800 just in case you want to go to a 1600MHz FSB CPU.

June 8, 2008 9:01:34 PM

Simply put, DDR3 will be worthwile with triple channel and a nehalem CPU. Until then, just pass it.

The only exception would be, if DDR3 drops to or below DDR2 price levels.
June 9, 2008 3:19:04 AM

DD3 is alot better value than it was 3 months ago. I like my ram running at the same speed as my CPU personally and depending on how much you want, I'd at least look at DDR3.
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June 9, 2008 3:26:58 AM

Spending money now on DDR3 is just like throwing money out the window. There is basically no reason to use it right now. And verigon what cpu are you running where DDR3 would be required to run 1:1(same speed)? Cause there isnt a cpu out that does need it. The skulltrail 1600FSB cpus only need DDR2800 to run at 1:1(same speed)
June 9, 2008 3:44:30 AM

Hi everyone, thanks for that feedback - I'm thinking DDR2 is the way to go, judging from everyone's comments, does anyone know the approx diff in $ between 8gig of DDR2 vs 8gig of DDR3 (DDR2 looks to be cheap, $100 for a kit etc) - still though if DDR3 is wasted, what's the point I guess...
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June 9, 2008 3:55:20 AM

Go to newegg and look through all ram kits/prices yourself. Its the best way to get a good understanding of how much the stuff costs. After you get a idea of the ram you want then check other retailers to see if you can find it cheaper or on sale
June 9, 2008 3:56:44 AM

thanks someguy, will do that : )
October 30, 2008 4:08:45 PM

The main difference between DDRII & DDRIII is latency & in most cases operating speed (Bandwidth). First you should understand latency, the interval between stimulus and response. CAS-2 you wait 2 clock cycles and for CAS-3 you wait 3 clock cycles.
The lower the CAS latency (given the same clock speed), the less time it takes to fetch data from it.
CAS latency (CL) is the time (in number of clock cycles) that elapses between the memory controller (CPU FBS) telling the memory module to access a particular column in the current row, and the data from that column being read from the module's output pins. CAS latency only specifies the delay between the request and the first bit. The clock speed specifies the latency between bits.
RAM manufacturers typically list the recommended timing for their RAM as a series of four integers separated by dashes (e.g 2-2-2-6 or 3-3-3-9 or 4-4-4-12 and so on). While there are many other settings related to RAM, these four integers refer to the following settings, which are typically listed in this order: CL - TRCD - TRP - TRAS.
CL = CAS Latency time: The time it takes between a command having been sent to the memory and when it begins to reply to it. It is the time it takes between the processor asking for some data from the memory and it returning it.
TRCD = DRAM RAS# to CAS# Delay: The number of clock cycles performed between activating the Row Access Strobe and the Column Access Strobe. This parameter relates to the time it takes to access stored data.
TRP = DRAM RAS# Precharge: The amount of time between the 'precharge' command and the 'active' command. The 'precharge' command closes memory that was accessed and the 'active' command signifies that a new read/write cycle can begin.
TRAS = Active to Precharge delay: The total time that will elapse between an active state and precharge state. This is the sum of the previous timings: CL + TRCD + TRP.

The main thing to look at between 800MHz & 1333MHz, again is the latency. Technically because 1333 operates faster it goes through clock cycles quicker then 800, but because it takes longer to access data per clock cycle (latency), the 1333 may not appear to be any faster than 800. Keep in mind that typically, the lower the CAS, the higher the price with in the same operating speed.

Something to consider is trying to match the (FBS) Front Bus Speed of the (MB) Motherboard, the (MCM) Memory Control Module AKA FBS of the CPU & the Operating speed or Bandwidth of the RAM. Here is an example configuration of this suggestion;
MB –
FSB 1066/800MHz


CPU –
FSB 800MHz


RAM –
Speed DDR2 800 (PC2 6400)

Cas Latency 4

Timing 4-4-4-12

October 30, 2008 4:24:39 PM

Heres a chart I put together, these are an average latency for given RAM. Check the manufactors site for details. One other note, newegg gives a link to the manufactors sites. When you click on a product, look in the bottm left corner for a manufactors info tab. In it you find a link to said product. Newegg is accurate with the info they give.
PC DDR Type MHz CAS Pin layout
DDR
PC 2100 2100 266 2.5 184
PC 2700 2700 333 2.5
PC 3200 3200 400 2.5
PC 4000 4000 500 3
DDR II
PC 3200 3200 400 3 240
PC 4200 4200 533 4
PC 5300 5300 667 5
PC 5400 5400 667 4
PC 5400 5400 675 4
PC 6400 6400 800 5
PC 8000 8000 1000 5
PC 8500 8500 1066 5
PC 8800 8800 1100 5
PC 8888 8888 1111 5
PC 9136 9136 1142 5
PC 9200 9200 1150 5
PC 9600 9600 1200 5
DDR III
PC 8500 8500 1066 7 240
PC 10600 10600 1333 9
PC 10660 10660 1333 6
PC 10666 10666 1333 6
PC 11000 11000 1375 7
PC 12800 12800 1600 9
PC 13000 13000 1625 8
PC 14400 14400 1800 8
PC 15000 15000 1866 8
PC 16000 16000 2000 9
PC 17066 17066 2133 9





September 29, 2009 3:54:01 PM

The determinant of memory for older systems is the front side bus(fsb) speed. I'm assuming your not an avid overclocker so here is what I know... The goal is to cover your front side bus band width ...if you fail to do that with a memory multiplier that does not support the bandwidth, the memory controller will clip the frequency of your memory and or bus until it gets close to a match. Avoid using memory that does not match the multiplier... an example would be: fsb 1333 dont use ddr2 or ddr3 800. modern motherboards will all do dual channel support ... that means you can use ddr2 667 mhz memory on a 1333mhz fsb and cover the entire band width(667 x 2= 1333 actual), and get a very small cas latency as low as 4 or even 3(the amount of latent time that data spends in memory as non-productive time), timings of 4-4-4-12 or 3-3-3-8 respectively where the first number is cas Latency. Always check your motherboard spec to see what type of memory is suported(could be ddr2, ddr3, or both). The more modern cpu supports hypertransport, qpi or dmi rather than allowing a separate memory controller on the motherboard. These Cpu determined speeds are normally noted as gt/s and are matched with memory in a different fashion, (gt/s)/2x1000=fsb speed where gt/s is the expressed speed of a serial memory bus.
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September 29, 2009 11:29:52 PM

If you were replying to the OP they left the room a YEAR ago.
!