What is BH5?
bh5 is known as THE overclockers memory around the world. it ran at 200mhz+ speeds with 2-2-2 timings WITHOUT a voltage bump even though it was rated to 166-200mhz 2.5-3-3.
chronically it all started with the winbond ah-6 wich already oced to 180mhz with 2-2-2 in the early DDR days with only pc2100 and pc2400 (100/133mhz) memory around.
later winbond released the bh-6, an improved ah-6 made in a smaller manufacturing process. those bh-6 chips are identical to bh5, bh5 are made in a yet smaller production process though, wich made them cheaper to manufacture and reduced the vdimm needed to reach certain speeds.
both, bh5 and bh6 oc to amazing speeds of 300mhz and more with very high vdimm voltage (4v+). the newest and last winbond ic is the ch-5, its a "crippled" bh5. the design was simplified to reduce the production costs yet again, unfortunatly it reduced the performence of those chips a bit, even though the newest ch5 chips seem to be able to run at 2-2-2 as well, their performence is still lower than bh5 or bh6 running at 2-2-2 timings.
i actually ran a few benchmarks and couldnt see any improvement at all between 2-3-2 and 2-2-2 with my stick of ch5. anyways, not all of those chips oc to amazing speeds around 300mhz. most max out at 240mhz (with around 3.2v) and some even max out a lot earlier (i had a stick that wouldnt even run 190mhz! with 3.2v).
winbond originally planned to introduce bh-4 memory, an improved ch-5 memory that could run 2-2-2 and reach much higher speeds as it was also built in the smaller 130nm process, unfortunately winbonds managers decided that the memory ic business was not lucrative enough with its massive fluctuations and samsung and hynix throwing their ic's on the market for next to nothing. furthermore none of the memory manufacturers realized the potential of the bh series and its marvelous capability to run with 2-2-2 timings at very high speeds. so only a very few bh-4 samples were ever made.
here is a pic of one:
http://xtremesystems.org/forums/atta...chmentid=17760
there are some bh-5 chips that have a very odd stepping code that doesnt match the usual bh-5 stepping code and i suspect those to be the few bh-4 chips from the first production line. there was no interest for bh-4 at that time so winbond could have relabeled their small bh-4 series to bh-5 to be able to sell them. it was the first series of bh-4, so that explains why they dont overclock extraordinarily compared to the normal bh-5 memory.
almost at the same time as overclockers and tweakers discovered bh-5 as beeing the best overclocking and tweaking memory by far, winbond had unfortunately already decided to leave the DRAM market. the request for bh-5, wich was used on cheap value ram by that time (!) was growing incredibly high. the bh-5 prices were rising by 20$ per stick for some days.
all manufacturers tried to get some of the very limited stock of bh-5 that was still available. mushkin and ocz released a last "limited edition" of memory based on bh5. as the demand for bh-5 memory kept rising and rising they kept looking for bh-5 stocks and found some bh-6 supply instead wich they used for the final bh series memory, another very limited "special edition" from ocz and muskin was released.
even today, almost 1 year after winbond dicontinued the bh-5 series, there is still no memory that matches its performence and overclockability. ocz has had a mayor success with its EB series wich runs at 2.5-2-2 or 3-2-2 yet still performs as well as bh-5 and bh-6 with 2-2-2 timings at the same speed, in some situations its even faster! this is possible due to some latency tweaking and improved pcb design from ocz.
however, the EB series overclocked slightly worse than bh-5 and bh-6 and needed 3-2-2 timings to reach high overclocks of 280-300mhz (on some good sticks) wich made it a little slow than bh-5 and bh-6 wich also reached 280-300 (on some good sticks).
in the meantime samsung has released a new memory ic, called tccd. this allround talent can run with 2-2-2 timings up to 230mhz, 2.5-3-3 timings up to 300mhz (on good sticks) and up to 340mhz with 3-4-4-8 timings (on good sticks). so it beats the bh-5/bh-6 series with brute force, a huge clockspeed, but still lacks the low latencies at high clockspeeds like the bh-5/bh-6 series that reaches 250-300mhz with 2-2-2 timings on average (!) on athlon64 boards with very high vdimm.
thats the history of the winbond bh-5/bh-6 legend... :D
winbond (and all ic manufacturers) are always looking to reduce the production costs and improve the yields to make more money, so they keep changing details in the manufacturing process and even the ic design. those changes mean that some steppings oc better than others (wich is the reason people ask for cpu steppings as well) wich was finally the reason why i came up with the idear to collect the steppings to give people an idear what chips probably oc better than others.
i did some more research on the manufacturing process of the diferent chips, and found this:
AH-6 180nm
BH-6 166nm
CH-6 166nm
AH-5 (doesnt exist?)
BH-5 150nm
CH-5 130nm
BH-4 130nm
this explains why bh-5 and bh-6 perform almost the same, they are made in almost the same manufacturing process.
i wrote this down before i and everybody else forgets all this infos about bh5 and bh6 and for those who are new to overclocking and dont know what all this bh5 and bh6 worshipping is all about :lol: furthermore bh5 and bh6 deserves to remembered for a long time :D
