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Lenovo Thinkpad T61 Slow PCMCIA Performance

On 2008-6-11 Lenovo released BIOS version 2.19 that specifically addresses this issue. Their changelog states:
"Version 7LETB9WW (2.19-1.08)
(Fix) Some CardBus and IEEE 1394 devices may slow down the performance"

You can download the 2.19 BIOS update here.

At the end of this page I've posted benchmarks showing the increased performance with the new BIOS.

While running benchmarks for one of my earlier articles, I discovered that the Lenovo T61 performed extremely poorly with PCMCIA (Cardbus) eSATA devices. Other laptops that were four years older than the T61 were outperforming it by a factor of two.

The Lenovo T61 is the fastest laptop in this comparison, yet it performs the poorest. But why?

My first instinct was to look at the PCMCIA/Cardbus Controller. The Lenovo Thinkpad T61 uses a Ricoh chipset. This was determined by looking in the Windows device manager.
The T61 uses a Ricoh R/RL/5C476(II) or Compatible Cardbus Controller. It is using the default microsoft cardbus controller driver.

Testing Method

Several laptops were compared that use various Cardbus controllers from Ricoh, Texas Instruments, and O2 Micro.

A Silicon Image Sil3112ACT144 Based SATA CardBus Card was used with a Seagate 500gb (ST3500630A) drive.

HDTune was used to measure Minimum, Maximum and Average speed in Megabytes per second. (MB/sec) Three tests were completed, and the results were averaged.

Here is a chart with all of the laptops used in this test. Notice that the Lenovo Thinkpad T61 has the most powerful processor, while the Compaq Evo N620C and the Dell D600 are four to five years old. The Pentium M, Banias core, was initially released in March 2003.

Laptop Model: Lenovo Thinkpad T61 Compaq nx6325 Compaq evo n620c Dell D600
Processor: Core 2 Duo T7100 1.8 Ghz Turion 64 X2 1.6ghz Pentium M 1.4ghz Pentium M 1.4ghz
Cardbus Controller: Ricoh R/RL/5C476(II) or Compatible Texas Instruments PCIxx12 O2Micro OZ5933 O2 Micro, Inc. OZ711EC1
Device IDs: VEN_1180 DEV_0476 VEN_104C DEV_8039 VEN_1217 DEV_6933


The Lenovo Thinkpad T61 which is less than one year old performed significantly worse than all of the others. The N620C and nx6325 performed the best, even though the N620C is over four years old. Clearly computer manufacturers are not looking at the Cardbus performance of their laptops. I do not have any other laptops that use the Ricoh chipset, so I do not know if this poor performance is due to the chip itself or poor implementation. Perhaps even a driver update can fix this issue, but I have not looked into that.

HDTune results in MB/sec
ModelLenovo T61Compaq nx6325Compaq n620cDell D600

Possible Causes?

The significant difference in performance could be caused by poorly written drivers, poor implementation of the chip, or perhaps it is just a poor performing device. In any case, I think Lenovo should investigate this issue further, and hopefully provide a solution.

The device manager shows a Ricoh R5C476 controller, yet Ricoh's website only shows an RC486 chip:
PC Card Controller LSI R5C485/R5C486
I opened my Thinkpad T61 to see what actual chip is controlling the cardbus slot. It turns out it uses the Ricoh RC5847, which is a combo device providing memory card and firewire functions along with the cardbus host.
Here's a picture of the actual chip inside my T61:
lenovo thinkpad t61 pcmcia cardbus controller ricoh r5c847
From Ricoh's website:
The R5C847 is a single chip solution offering six PCI functions (a PCI bus bridge to a PC Card, an IEEE1394, an SD Card, a MultiMediaCard, a Memory Stick, and an xD Picture Card via a PC Card) with an ExpressCard (USB Interface Type) switch. Almost all the Flash Memory Cards currently in the market, allowing system designers to flexibly configure systems necessary to interface with multiple Flash Memory Cards.

This may be a case similar to a multi-function printer. The device may have many features, but rather than excelling in one function it performs many functions only marginally well.

I've contacted Ricoh asking for the expected performance from this chip, but I have a feeling I won't hear back from them.

Searching for the chip itself points to a website that states:
If your ThinkPad is not listed below, you probably don't have this chip but one of the newer Ricoh chips, that emulates this chips CardBus functions (including PCI ID) for backwards compatibility

Perhaps the linux drivers for this particular chip are more advanced than the windows drivers. Unfortunately I don't know enough about Linux to test this.

Further Testing

To determine if the bottleneck here is actually caused by the cardbus controller this test was devised. The low performance of the esata on the T61 could be caused by a poor esata to cardbus controller, so I tested two diferent controllers from two different manufacturers, using three different notebook computers.
tested with HDTach.
In addition to the Compaq n620c and Lenovo T61 used above, a Toshiba Satellite 2508 was used. This is a Celeron 700mhz notebook that is 8 years old.

Note the Windows ME and Celeron stickers on the 8 year old Toshiba Satellite used in this test.

A Seagate 160GB SATA Hard drive (Model: ST316081) is connected to a eSATA enclosure (Model: CRU Data-Portable 350) purcahsed from CDW.

These are the esata to cardbus devices used in this test:
Silicon Image 3112 based SATA Cardbus card:
Generic Card Purchased from ebay $30

Initio INIC-1620TA2 based eSATA Cardbus card:
StarTech CBESATA2 purchased from Newegg.com ($34.99)

As a control test, an Expresscard was used. The expresscard bus provides significantly more bandwidth than Cardbus.
Silicon Image 3132 based eSATA Expresscard card:
SIIG SC-SAEE22-S1 purchased from CDW.com ($69.99)


HDTune Results, Maximum Transfer Rate
Computer Cardbus Silicon Image 3112: Cardbus Initio INIC-1620TA2: Expresscard Silicon Image 3132:
Lenovo T61 14.0 MB/sec 10.9 MB/sec 75.1 MB/sec
Compaq n620c 38.5 MB/sec 75.1 MB/sec No Expresscard Slot
Toshiba Satellite 2508 75.1 MB/sec 74.6 MB/sec No Expresscard Slot

Notice that the 8 year old laptop has outperformed both laptops in Cardbus performance.

Lenovo Thinkpad T61 Results:

Cardbus Silicon Image 3112: Cardbus Initio INIC-1620TA2: Expresscard Silicon Image 3132:

Compaq n620c Results:

Cardbus Silicon Image 3112: Cardbus Initio INIC-1620TA2: Expresscard Silicon Image 3132:
No Expresscard Slot

Toshiba Satellite 2508 Results:

Cardbus Silicon Image 3112: Cardbus Initio INIC-1620TA2: Expresscard Silicon Image 3132:
No Expresscard Slot


On an eight year old laptop, the Initio and Silicon Image based cards perform over SEVEN TIMES faster than the brand new Lenovo T61. The bandwidth is limited by the hard drive used in this test rather than the esata card or the cardbus interface.
Clearly the Initio 1620TA2 based sata cardbus card provides enough capacity to rival the performance of the expresscard based card on more platforms, as it is very fast on the 4 year old and 8 year old laptops.
This further enforces the hypothesis that the performance of the cardbus slot on the Lenovo T61 is severly limited.
A faster hard drive is required to test the capacity limits of these cards.


In an exciting development, Lenovo has decided to address this issue in their latest BIOS version. Update your BOIS to version 2.19 to see a 500% increase in the performance of your Cardbus slot. It's still a little below the maximum speed I've seen with other laptops using this same drive and cardbus configuration, but it's still SIGNIFICANTLY better than before. Thank you Lenovo!

You can download the 2.19 BIOS update here.

Here I am comparing the factory BIOS (2.12) with the latest bios with the pcmcia fix (2.19):

Lenoto T61 eSATA PCMCIA Performance
in MB/sec
 2.12  2.19 <- BIOS Version
eSATA Cardbus controller:
11.059.8InitIO INIC-1620TA2
14.057.8Silicon Image sil3112
14.057.9Silicon Image sil3512

Here are the same results, along with the results using the same cardbus cards, and same hard drives on an 8 year old toshiaba laptop.

If anyone has any more information regarding the speed of the T61 cardbus interface please contact me.

Revision History
3-21-2008 - Page Initially Created
3-24-2008 - Updated with R5C847 info
3-25-2008 - Fixed a few consistency and grammar errors
4-10-2008 - Added esata cardbus comparison "further testing" with initio results
6-19-2008 - Added information regarding BIOS v2.19

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